Butanedione

This chemical does not meet GHS hazard criteria for 0.3% (6 of 1782) of reports.

H225 (98.3%): Highly Flammable liquid and vapor [Danger Flammable liquids]

H302 (87.4%): Harmful if swallowed [Warning Acute toxicity, oral]

H315 (99.7%): Causes skin irritation [Warning Skin corrosion/irritation]

H317 (84%): May cause an allergic skin reaction [Warning Sensitization, Skin]

H318 (97.4%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

H331 (97.1%): Toxic if inhaled [Danger Acute toxicity, inhalation]

H373 (84.1%): May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]

P210, P233, P240, P241, P242, P243, P260, P261, P264, P264+P265, P270, P271, P272, P280, P301+P317, P302+P352, P303+P361+P353, P304+P340, P305+P354+P338, P316, P317, P319, P321, P330, P332+P317, P333+P317, P362+P364, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 1782 reports by companies from 35 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Reported as not meeting GHS hazard criteria per 6 of 1782 reports by companies.

There are 34 notifications provided by 1776 of 1782 reports by companies with hazard statement code(s).

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

H225 (100%): Highly Flammable liquid and vapor [Danger Flammable liquids]

H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]

H315 (100%): Causes skin irritation [Warning Skin corrosion/irritation]

H318 (100%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

H332 (100%): Harmful if inhaled [Warning Acute toxicity, inhalation]

H335 (100%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

P210, P233, P240, P241, P242, P243, P261, P264, P264+P265, P270, P271, P280, P301+P317, P302+P352, P303+P361+P353, P304+P340, P305+P354+P338, P317, P319, P321, P330, P332+P317, P362+P364, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 38 reports by companies from 1 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

H225: Highly Flammable liquid and vapor [Danger Flammable liquids]

H315: Causes skin irritation [Warning Skin corrosion/irritation]

H317: May cause an allergic skin reaction [Warning Sensitization, Skin]

H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]

H331: Toxic if inhaled [Danger Acute toxicity, inhalation]

H351: Suspected of causing cancer [Warning Carcinogenicity]

H370: Causes damage to organs [Danger Specific target organ toxicity, single exposure]

H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]

P203, P210, P233, P240, P241, P242, P243, P260, P261, P264, P264+P265, P270, P271, P272, P280, P302+P352, P303+P361+P353, P304+P340, P305+P354+P338, P308+P316, P316, P317, P318, P319, P321, P332+P317, P333+P317, P362+P364, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

P210, P233, P240, P241, P242, P243, P260, P261, P264, P264+P265, P270, P272, P280, P302+P352, P303+P361+P353, P305+P354+P338, P308+P316, P317, P319, P321, P332+P317, P333+P317, P362+P364, P370+P378, P403+P235, P405, and P501 (click each P-code to see the statement)

H302: Harmful if swallowed [Warning Acute toxicity, oral]

H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

P210, P233, P240, P241, P242, P243, P261, P264, P264+P265, P270, P271, P280, P301+P317, P302+P352, P303+P361+P353, P304+P340, P305+P354+P338, P316, P317, P319, P321, P330, P332+P317, P362+P364, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Fresh air, rest. Refer for medical attention.

Remove contaminated clothes. Rinse skin with plenty of water or shower.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Give one or two glasses of water to drink. Seek medical attention if you feel unwell.

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: DO NOT INDUCE VOMITING. Volatile chemicals have a high risk of being aspirated into the victim's lungs during vomiting which increases the medical problems. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. IMMEDIATELY transport the victim to a hospital. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital. (NTP, 1992)

General First Aid:

· Call 911 or emergency medical service.

· Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination.

· Move victim to fresh air if it can be done safely.

· Administer oxygen if breathing is difficult.

· If victim is not breathing:

-- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance.

-- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).

-- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.

· Remove and isolate contaminated clothing and shoes.

· For minor skin contact, avoid spreading material on unaffected skin.

· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.

· For severe burns, immediate medical attention is required.

· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.

· Keep victim calm and warm.

· Keep victim under observation.

· For further assistance, contact your local Poison Control Center.

· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.

Specific First Aid:

· Wash skin with soap and water.

· In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin.

In Canada, an Emergency Response Assistance Plan (ERAP) may be required for this product. Please consult the shipping paper and/or the "ERAP" section.

Excerpt from ERG Guide 127 [Flammable Liquids (Water-Miscible)]:

CAUTION: The majority of these products have a very low flash point. Use of water spray when fighting fire may be inefficient. CAUTION: For fire involving UN1170, UN1987 or UN3475, alcohol-resistant foam should be used. CAUTION: Ethanol (UN1170) can burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.).

SMALL FIRE: Dry chemical, CO2, water spray or alcohol-resistant foam.

LARGE FIRE: Water spray, fog or alcohol-resistant foam. Avoid aiming straight or solid streams directly onto the product. If it can be done safely, move undamaged containers away from the area around the fire.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2024)

Use powder, alcohol-resistant foam, water spray, carbon dioxide. In case of fire: keep drums, etc., cool by spraying with water.

Suitable extinguishing media: For small (incipient) fires, use media such as "alcohol" foam, dry chemical, or carbon dioxide. For large fires, apply water from as far as possible. Use very large quantities (flooding) of water applied as a mist or spray; solid streams of water may be ineffective. Cool all affected containers with flooding quantities of water.

Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary.

Use water spray to cool unopened containers.

To fight fire, use alcohol foam, CO2, dry chemical.

For more Fire Fighting Procedures (Complete) data for DIACETYL (6 total), please visit the HSDB record page.

Vapors are heavier than air and will collect in low areas. Vapors may travel long distances to ignition sources and flashback. Vapors in confined areas may explode when exposed to fire. Storage containers and parts of containers may rocket great distances, in many directions.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· Keep unauthorized personnel away.

· Stay upwind, uphill and/or upstream.

· Ventilate closed spaces before entering, but only if properly trained and equipped.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.

· All equipment used when handling the product must be grounded.

· Do not touch or walk through spilled material.

· Stop leak if you can do it without risk.

· Prevent entry into waterways, sewers, basements or confined areas.

· A vapor-suppressing foam may be used to reduce vapors.

· Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers.

· Use clean, non-sparking tools to collect absorbed material.

Large Spill

· Dike far ahead of liquid spill for later disposal.

· Water spray may reduce vapor, but may not prevent ignition in closed spaces.

Excerpt from ERG Guide 127 [Flammable Liquids (Water-Miscible)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 50 meters (150 feet) in all directions.

LARGE SPILL: Consider initial downwind evacuation for at least 300 meters (1000 feet).

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

Immediate precautionary measure

· Isolate spill or leak area for at least 50 meters (150 feet) in all directions.

· Consider initial downwind evacuation for at least 300 meters (1000 feet).

· If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions.

Remove all ignition sources. Personal protection: filter respirator for organic gases and vapours adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Collect leaking liquid in covered containers. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Wear respiratory protection. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Remove all sources of ignition. Evacuate personnel to safe areas. Beware of vapors accumulating to form explosive concentrations. Vapors can accumulate in low areas. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Methods and materials for containment and cleaning up: Contain spillage, and then collect with an electrically protected vacuum cleaner or by wet-brushing and place in container for disposal according to local regulations.

Evacuate and restrict persons not wearing protective equipment from area of spill or leak until cleanup is complete. Remove all ignition sources. Ventilate area of spill or leak. Absorb liquids in vermiculite, dry sand, earth, or a similar material and deposit in sealed containers. Keep butanedione out of confined space, such as a sewer, because of the possibility of an explosion, unless the sewer is designed to prevent the build up of explosive concentrations. It may be necessary to contain and dispose of this chemical as a hazardous waste. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters.

Environmental considerations--land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash, cement powder, or commercial sorbents.

Environmental considerations--water spill: Use natural barriers or oil spill control booms to limit spill travel. Remove trapped material with suction hoses.

Environmental considerations--air spill: Apply water spray or mist to knock down vapors.

SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

Product: Burn in a chemical incinerator equipped with an afterburner and scrubber but exert extra care in igniting as this material is highly flammable. Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this material. Contaminated packaging: Dispose of as unused product.

Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Wear respiratory protection. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Remove all sources of ignition. Evacuate personnel to safe areas. Beware of vapors accumulating to form explosive concentrations. Vapors can accumulate in low areas. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains.

Precautions for safe handling: Use with local exhaust ventilation. Avoid contact with skin and eyes. Avoid inhalation of vapor or mist. Avoid contact with skin and eyes. Avoid inhalation of vapor or mist. Use explosion-proof equipment. Keep away from sources of ignition - No smoking. Take measures to prevent the build up of electrostatic charge.

Appropriate engineering controls: This compound should be handled in a closed system. All operations should be carried out in a glove bag or similar enclosure to avoid accidental contact. Avoid contact with skin, eyes and clothing. Wash hands before breaks and immediately after handling the product.

Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.

For more Preventive Measures (Complete) data for DIACETYL (9 total), please visit the HSDB record page.

Excerpt from ERG Guide 127 [Flammable Liquids (Water-Miscible)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. All equipment used when handling the product must be grounded. Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. A vapor-suppressing foam may be used to reduce vapors. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. Use clean, non-sparking tools to collect absorbed material.

LARGE SPILL: Dike far ahead of liquid spill for later disposal. Water spray may reduce vapor, but may not prevent ignition in closed spaces. (ERG, 2024)

Fireproof. Store in an area without drain or sewer access. Separated from : see Chemical Dangers.

Store in cool place. Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Recommended storage temperature 2 - 8 °C. Storage class (TRGS 510): Flammable liquids.

Store in a flammable liquid storage area or approved cabinet away from ignition sources and corrosive and reactive materials. Store in tightly closed containers in a cool, well-ventilated area. Sources of ignition, such as smoking and open flames, are prohibited where butanedione is used, handled, or stored in a manner that could create a potential fire or explosion hazard. Metal containers involving the transfer of 5 gallons or more of butanedione should be grounded and bonded. Drums must be equipped with self-closing valves, pressure vacuum bungs and flame arresters. Use only nonsparking tools and equipment, especially when opening and closing containers of butanedione. Wherever butanedione is used, handled, manufactured, or stored, use explosion-proof electrical equipment and fittings.

· Wear positive pressure self-contained breathing apparatus (SCBA).

· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

0.02 [ppm]

0.070 [mg/m3]

52 [mg/m3]

310 [mg/m3]

5 ppb (0.005 ppm) 8-hr TWA [2.6 ppb (0.0026 ppm) Action Level]

25 ppb (0.025 ppm) [15 minutes]

0.01 [ppm]

8 hr Time Weighted Avg (TWA): 0.01 ppm; 15 min Short Term Exposure Limit (STEL): 0.02 ppm.

A4: Not classifiable as a human carcinogen.

0.01 ppm as TWA; 0.02 ppm as STEL; A4 (not classifiable as a human carcinogen).

0.01 ppm [2011]

0.02 ppm [2011]

0.07 mg/m

0.071 mg/m

CAUTION: The majority of these products have a very low flash point. Use of water spray when fighting fire may be inefficient.

CAUTION: For fire involving UN1170, UN1987 or UN3475, alcohol-resistant foam should be used.

CAUTION: Ethanol (UN1170) can burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.)

Small Fire

· Dry chemical, CO2, water spray or alcohol-resistant foam.

Large Fire

· Water spray, fog or alcohol-resistant foam.

· Avoid aiming straight or solid streams directly onto the product.

· If it can be done safely, move undamaged containers away from the area around the fire.

Fire Involving Tanks, Rail Tank Cars or Highway Tanks

· Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles.

· Cool containers with flooding quantities of water until well after fire is out.

· Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank.

· ALWAYS stay away from tanks in direct contact with flames.

· For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn.

No indication can be given about the rate at which a harmful concentration of this substance in the air is reached on evaporation at 20 °C.

The substance is severely irritating to the eyes. The substance is irritating to the skin and respiratory tract. The substance may cause effects on the central nervous system, lungs and respiratory tract. Exposure at high levels could cause lowering of consciousness.

Lungs may be affected by repeated or prolongated exposure to the vapour. This may result in impaired functions.

Excerpt from ERG Guide 127 [Flammable Liquids (Water-Miscible)]:

Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing provides thermal protection but only limited chemical protection. (ERG, 2024)

Eye/face protection: Tightly fitting safety goggles. Faceshield (8-inch minimum). Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).

Skin protection: Handle with gloves.

Body Protection: Long sleeved clothing. Preventive skin protection. Complete suit protecting against chemicals. Flame retardant antistatic protective clothing. The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.

Respiratory protection: PAPR (powered air purifying respirator) with organic vapor cartridges and particulate filters are acceptable during mixing activities. Where risk assessment shows air-purifying respirators are appropriate use a full-face respirator with multipurpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls. If the respirator is the sole means of protection, use a full-face supplied air respirator. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).

Diacetyl appears as a clear colorless liquid with a strong chlorine-like odor. Flash point 80 °F. Less dense than water. Vapors heavier than air.

Clear liquid with a chlorine-like odor; [CAMEO]

GREEN-TO-YELLOW LIQUID.

yellow to yellow-green liquid with a powerful, buttery odour in very dilute solution

Colorless liquid with a strong chlorine-like odor.

Greenish-yellow liquid

Yellow liquid

Quinone odor; vapors have a chlorine-like odor

Very strong buttery odor in dilute solution

Strong odor

Taste characteristics at 50 ppm: sweet, buttery, creamy and milky

Threshold taste detection in milk (gas chromatically pure): 1.40X10-2 ppm and 2.90X10-2 ppm; in skim milk: 1.00X10-1 ppm

Threshold taste detection in water (gas chromatically pure): 5.40X10-3 ppm; in water: 1.00X10-8% (volume/volume or wg/wg).

190 °F at 760 mmHg (NTP, 1992)

87.00 to 88.00 °C. @ 760.00 mm Hg

87-88 °C

88 °C @760 [mm Hg]

27.7 °F (NTP, 1992)

80 °F (NTP, 1992)

7 °C (45 °F) - closed cup

80 °F (27 °C) (closed cup)

6 °C c.c.

greater than or equal to 100 mg/mL at 72 °F (NTP, 1992)

In water, 200 g/L at 20 °C

Soluble in about 4 parts water

Readily soluble in all important organic solvents

Miscible with ether

For more Solubility (Complete) data for DIACETYL (8 total), please visit the HSDB record page.

200 mg/mL at 15 °C

Solubility in water, g/100ml at 25 °C: 20

soluble in glycerol and water; miscible with alcohol, propylene glycol, and most fixed oils

(in ethanol)

0.99 at 59 °F (NTP, 1992) - Less dense than water; will float

0.990 at 15 °C/15 °C

Relative density (water = 1): 1.1

0.975-0.990

0.99 at 59 °F

0.990 @ 15°C

3 (NTP, 1992) - Heavier than air; will sink (Relative to Air)

3.00 (Air = 1)

Highly flammable. Soluble in water.

Highly Flammable

DIACETYL is a flammable liquid, b.p. 88 °C, moderately toxic. When heated to decomposition it emits acrid smoke and fumes [Sax, 9th ed., 1996, p. 544].

Incompatible materials: Oxidizing agents, strong bases, reducing agents, metals

Contact with oxidizers may cause fire and explosions. High heat may cause violent combustion or explosion.

IDENTIFICATION AND USE: Diacetyl (DA) is a yellow liquid. It is used as synthetic flavoring substance and adjuvant. Diacetyl has been widely used as a chemical modifier of proteins, combining with arginine residues. HUMAN EXPOSURE AND TOXICITY: Diacetyl is a diketone flavoring agent that is commonly employed for buttery taste as well as other purposes. Industrial exposure to flavoring agents, particularly diacetyl, has recently been associated with bronchiolitis obliterans, a severe respiratory illness producing fibrosis and obstruction of the small airways. This has been most commonly reported in the microwave popcorn production industry, but it has occurred elsewhere. In addition to bronchiolitis obliterans, spirometry abnormalities (fixed airflow obstruction) and respiratory symptoms have been associated with exposure. A direct effect on the respiratory epithelium with the disorganized fibrotic repair appears most likely as the underlying mechanism. Current data suggest that diacetyl is the agent responsible, although it is possible that diacetyl is simply a marker for another causative agent. Workers at the microwave popcorn company experienced normal rates of all-cause mortality but higher rates of chronic obstructive pulmonary disease-associated mortality, especially workers employed before the company reduced diacetyl exposure. According to case reports, lung disease could also arise in the consumers of diacetyl-containing popcorn. ANIMAL STUDIES: Male mice were exposed by inhalation to 200 or 400 ppm DA 6 hr/day for 5 days. 400 ppm caused deaths and acute necrotizing rhinitis, laryngitis and bronchitis (proximal large bronchi). Exposure to 200 ppm caused a few deaths and acute necrotizing rhinitis and erosive or necrotizing laryngitis in all mice. There were no lung or bronchiolar lesions in the DA exposed mice. Chronic bronchitis, laryngitis, and rhinitis were present after 2 and 4 weeks of exposure. In rats diacetyl inhalation increases substance P levels in sensory nerves of airway epithelium. Because substance P release in airways promotes inflammation and activation of sensory nerves mediates reflexes, neural changes may contribute to flavorings-related lung disease pathogenesis. When given i.p. to mice once weekly for 24 weeks, diacetyl (1.70 or 8.40 mg/kg [0.0197 or 0.0976 mmol/kg]) did not induce any lung tumors. Groups of hamsters, mice, and rats were given a solution containing 90% diacetyl by gavage on days 6-10 of gestation for hamsters and days 6-15 of gestation for mice and rats. The doses for all species were 16, 74, 345, or 1600 mg/kg bw per day. No effects were seen on maternal survival, weight, or reproductive parameters or on fetal survival or microscopic appearance of external, skeletal, or soft tissues. Diacetyl induced mitotic chromosome loss in Saccharomyces cerevisiae in the presence of propionitrile. In several bacterial assays, diacetyl generally showed mutagenic activity in Salmonella typhimurium strains TA100, 102, and 104 with and without metabolic activation but none against strain TA98. Conflicting results were obtained in Escherichia coli strain WP2 uvra, but nonmutagenicity was demonstrated in the SOS-chromotest using E. coli PQ37. Diacetyl was also negative in a micronucleus test using mouse bone marrow cells.

Diacetyl is a cholinesterase or acetylcholinesterase (AChE) inhibitor. A cholinesterase inhibitor (or 'anticholinesterase') suppresses the action of acetylcholinesterase. Because of its essential function, chemicals that interfere with the action of acetylcholinesterase are potent neurotoxins, causing excessive salivation and eye-watering in low doses, followed by muscle spasms and ultimately death. Nerve gases and many substances used in insecticides have been shown to act by binding a serine in the active site of acetylcholine esterase, inhibiting the enzyme completely. Acetylcholine esterase breaks down the neurotransmitter acetylcholine, which is released at nerve and muscle junctions, in order to allow the muscle or organ to relax. The result of acetylcholine esterase inhibition is that acetylcholine builds up and continues to act so that any nerve impulses are continually transmitted and muscle contractions do not stop. Among the most common acetylcholinesterase inhibitors are phosphorus-based compounds, which are designed to bind to the active site of the enzyme. The structural requirements are a phosphorus atom bearing two lipophilic groups, a leaving group (such as a halide or thiocyanate), and a terminal oxygen.

A4: Not classifiable as a human carcinogen.

2,3-Butanedione

TR-593: Toxicology and Carcinogenesis Studies of 2,3-Butanedione (CASRN 431-03-8) in Wistar Han [Crl:WI (Han)] Rats and B6C3F1/N Mice (Inhalation Studies) (2018 )

07/13/17

Some Evidence

No Evidence

Equivocal Evidence

Under the conditions of these 2-year inhalation studies, there was some evidence of carcinogenic activity of 2,3-butanedione in male Wistar Han rats based on the combined incidences of squamous cell papilloma and squamous cell carcinoma of the nose. There was some evidence of carcinogenic activity of 2,3-butanedione in female Wistar Han rats based on the incidences of squamous cell carcinoma of the nose. There was no evidence of carcinogenic activity of 2,3-butanedione in male B6C3F1/N mice exposed to 12.5, 25, or 50 ppm. There was equivocal evidence of carcinogenic activity of 2,3-butanedione in female B6C3F1/N mice based on the occurrences of adenocarcinoma of the nose.

Exposure to 2,3-butanedione resulted in increased incidences of nonneoplastic lesions of the nose, larynx, trachea, lung, and eye in male and female rats and mice.

No indication of carcinogenicity (not listed by IARC). (L135)

Acute exposure to cholinesterase inhibitors can cause a cholinergic crisis characterized by severe nausea/vomiting, salivation, sweating, bradycardia, hypotension, collapse, and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Accumulation of ACh at motor nerves causes overstimulation of nicotinic expression at the neuromuscular junction. When this occurs symptoms such as muscle weakness, fatigue, muscle cramps, fasciculation, and paralysis can be seen. When there is an accumulation of ACh at autonomic ganglia this causes overstimulation of nicotinic expression in the sympathetic system. Symptoms associated with this are hypertension, and hypoglycemia. Overstimulation of nicotinic acetylcholine receptors in the central nervous system, due to accumulation of ACh, results in anxiety, headache, convulsions, ataxia, depression of respiration and circulation, tremor, general weakness, and potentially coma. When there is expression of muscarinic overstimulation due to excess acetylcholine at muscarinic acetylcholine receptors symptoms of visual disturbances, tightness in chest, wheezing due to bronchoconstriction, increased bronchial secretions, increased salivation, lacrimation, sweating, peristalsis, and urination can occur. Certain reproductive effects in fertility, growth, and development for males and females have been linked specifically to organophosphate pesticide exposure. Most of the research on reproductive effects has been conducted on farmers working with pesticides and insecticdes in rural areas. In females menstrual cycle disturbances, longer pregnancies, spontaneous abortions, stillbirths, and some developmental effects in offspring have been linked to organophosphate pesticide exposure. Prenatal exposure has been linked to impaired fetal growth and development. Neurotoxic effects have also been linked to poisoning with OP pesticides causing four neurotoxic effects in humans: cholinergic syndrome, intermediate syndrome, organophosphate-induced delayed polyneuropathy (OPIDP), and chronic organophosphate-induced neuropsychiatric disorder (COPIND). These syndromes result after acute and chronic exposure to OP pesticides.

The substance can be absorbed into the body by inhalation and by ingestion.

Oral (L1280) ; inhalation (L1280) ; dermal (L1280) ; eye contact (L1280)

Cough. Drowsiness. Nausea. Headache. Sore throat.

Redness.

Redness. Pain. Burns.

Sore throat.

Causes eye irritation, redness and pain. Causes moderate skin irritation. Harmful if swallowed. May cause gastrointestinal irritation with nausea, vomiting and diarrhea. Causes respiratory tract irritation. Vapors may cause dizziness or suffocation. Harmful if inhaled. High exposure to butanedione may cause headache, drowsiness, lack of coordination and seizures (L1280).

Skin Sensitizer - An agent that can induce an allergic reaction in the skin.

Fibrogenic - Inducing tissue injury and fibrosis (scarring).

ACGIH Carcinogen - Confirmed Animal.

LD50: 1580 mg/kg (Oral, Rat) (L1280)

LD50: >5 gm/kg (Dermal, Rabbit) (L1280)

LD50 Rat male gavage 3400 mg/kg bw

LD50 Rat female gavage 3000 mg/kg bw

LD50 Rat gavage 1580 mg/kg bw

LD50 Mouse oral 250 mg/kg

For more Non-Human Toxicity Values (Complete) data for DIACETYL (6 total), please visit the HSDB record page.

If the compound has been ingested, rapid gastric lavage should be performed using 5% sodium bicarbonate. For skin contact, the skin should be washed with soap and water. If the compound has entered the eyes, they should be washed with large quantities of isotonic saline or water. In serious cases, atropine and/or pralidoxime should be administered. Anti-cholinergic drugs work to counteract the effects of excess acetylcholine and reactivate AChE. Atropine can be used as an antidote in conjunction with pralidoxime or other pyridinium oximes (such as trimedoxime or obidoxime), though the use of '-oximes' has been found to be of no benefit, or possibly harmful, in at least two meta-analyses. Atropine is a muscarinic antagonist, and thus blocks the action of acetylcholine peripherally.

"Popcorn workers' lung" is an obstructive pulmonary disease produced by inhalation of volatile artificial butter flavorings. In rats, inhalation of diacetyl, a major component of butter flavoring, and inhalation of a diacetyl substitute, 2,3-pentanedione, produce similar damage to airway epithelium. The effects of diacetyl and 2,3-pentanedione and mixtures of diacetyl, acetic acid, and acetoin, all components of butter flavoring, on pulmonary function and airway reactivity to methacholine (MCh) were investigated. Lung resistance (RL) and dynamic compliance (Cdyn) were negligibly changed 18 hr after a 6-hr inhalation exposure to diacetyl or 2,3-pentanedione (100-360 ppm). Reactivity to MCh was not markedly changed after diacetyl, but was modestly decreased after 2,3-pentanedione inhalation. Inhaled diacetyl exerted essentially no effect on reactivity to mucosally applied MCh, but 2,3-pentanedione (320 and 360 ppm) increased reactivity to MCh in the isolated, perfused trachea preparation (IPT). In IPT, diacetyl and 2,3-pentanedione (>/= 3 mM) applied to the serosal and mucosal surfaces of intact and epithelium-denuded tracheas initiated transient contractions followed by relaxations. Inhaled acetoin (150 ppm) exerted no effect on pulmonary function and airway reactivity in vivo; acetic acid (27 ppm) produced hyperreactivity to MCh; and exposure to diacetyl + acetoin + acetic acid (250 + 150 + 27 ppm) led to a diacetyl-like reduction in reactivity. Data suggest that the effects of 2,3-pentanedione on airway reactivity are greater than those of diacetyl, and that flavorings are airway smooth muscle relaxants and constrictors, thus indicating a complex mechanism.

Diacetyl induced mitotic chromosome loss in Saccharomyces cerevisiae in the presence of propionitrile.[Integrated Laboratory Systems, Inc.; Chemical Information Review Document for Artificial Butter Flavoring and Constituents Diacetyl [CAS No. 431-03-8] and Acetoin

In CHO AUXB1 cells, bisulfite significantly reduced the frequency of SCEs and proportion of endoreduplicated cells when diacetyl was administered. Sodium sulfite and heterocyclic amines inactivated the mutagenicity of diacetyl in S. typhimurium strain TA100.[Integrated Laboratory Systems, Inc.; Chemical Information Review Document for Artificial Butter Flavoring and Constituents Diacetyl [CAS No. 431-03-8] and Acetoin

Reuterin (beta-hydroxypropionialdehyde) is a broad-spectrum antimicrobial substance produced by some strains of Lactobacillus reuteri during anaerobic fermentation of glycerol. Some of these strains are able to survive and produce reuterin in cheese and yogurt when added as adjuncts to the starter. Similarly, in fermented dairy foods, other inhibitory compounds such as lactic acid and diacetyl are produced during fermentation. In this work, we studied the combined effect of reuterin and diacetyl under different pH conditions against Escherichia coli O157:H7, Salmonella enteritidis, and Listeria monocytogenes. Results from agar spot assays showed that the antimicrobial activity of reuterin-producing strains against the gram-negative bacteria tested was enhanced as the concentration of diacetyl increased to 50 mg/kg, and was higher under acidic conditions (pH 5.0) for the 3 pathogenic strains. The combination of reuterin and diacetyl had an additive effect against L. monocytogenes only at diacetyl concentrations of 50 mg/kg and pH 5.0. In addition, growth kinetics studies showed that the combination of 1 activity unit (AU)/mL of reuterin with 100mg/kg diacetyl increased the lag time of the 3 pathogens. In milk, synergistic antimicrobial activity was observed with the combination of 1 AU/mL reuterin and 50 or 100 mg/kg of diacetyl on the gram-negative strains tested, and with 1 AU/mL reuterin and 100 mg/kg of diacetyl on L. monocytogenes. The greatest inhibition of the 3 pathogens was achieved in acidified milk at pH 5.0 with reuterin (1 AU/mL) and diacetyl (100 mg/kg). Based on these results, the combination of reuterin and diacetyl in acidified dairy products could be a promising strategy to control food pathogens in these products.

Immediate First Aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention.

Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . For contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . /Ketones and related compounds/

Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag-valve-mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Ketones and related compounds/

If this chemical gets into the eyes, remove any contact lenses at once and irrigate immediately for at least 15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the skin, remove contaminated clothing and wash immediately with soap and water. Seek medical attention immediately. If this chemical has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if heart action has stopped. Transfer promptly to a medical facility. When this chemical has been swallowed, get medical attention.

/SIGNS AND SYMPTOMS/ Diacetyl is a diketone flavoring agent that is commonly employed for buttery taste as well as other purposes. Industrial exposure to flavoring agents, particularly diacetyl, has recently been associated with bronchiolitis obliterans, a severe respiratory illness producing fibrosis and obstruction of the small airways. This has been most commonly reported in the microwave popcorn production industry, but it has occurred elsewhere. In addition to bronchiolitis obliterans, spirometry abnormalities (fixed airflow obstruction) and respiratory symptoms have been associated with exposure. A direct effect on the respiratory epithelium with the disorganized fibrotic repair appears most likely as the underlying mechanism. Current data suggest that diacetyl is the agent responsible, although it is possible that diacetyl is simply a marker for another causative agent.

/CASE REPORTS/ Respiratory exposure to diacetyl and diacetyl-containing flavorings used in butter-flavored microwave popcorn (BFMP) causes lung disease, including bronchiolitis obliterans (BO), in flavorings and popcorn manufacturing workers. However, there are no published reports of lung disease among BFMP consumers. We present a case series of three BFMP consumers with biopsy-confirmed BO. We review data relating to consumer exposures, estimate case exposures, and compare them to diacetyl-containing flavoring-exposed manufacturing workers with lung disease. These consumer cases' exposure levels are comparable to those that caused disease in workers. We were unable to identify any other exposures or diseases known or suspected to cause BO in these cases. BFMP poses a significant respiratory risk to consumers. Some manufacturers have substituted diacetyl with other alpha-diketones that are likely to pose a similar risk. Simple consumer practices such as cooling the popcorn bag would eliminate the risk of severe lung disease.

The substance is harmful to aquatic organisms. Environmental effects from the substance have not been investigated adequately.

Diacetyl's production and use as a synthetic flavoring substance and carrier of aroma of butter, vinegar, coffee and other foods and use in e-cigarette flavorings may result in its release to the environment through various waste streams. Diacetyl is found in butter, bay oil and other oils; plant volatiles, forest fires, animal wastes; tree ripened whole nectarine; kiwi fruit flower; and as a natural product of fermentation. Diacetyl has been identified as a component of tobacco smoke. If released to air, a vapor pressure of 56.8 mm Hg at 25 °C indicates diacetyl will exist solely as a vapor in the atmosphere. Vapor-phase diacetyl will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 67 days. Diacetyl contains chromophores that absorb at wavelengths >290 nm and, therefore, may be susceptible to direct photolysis by sunlight. The direct photolysis half-life of diacetyl in the atmosphere has been reported at 0.7 hr. If released to soil, diacetyl is expected to have very high mobility based upon a estimated Koc of 1. Volatilization from moist soil surfaces is expected to be an important fate process based upon a Henry's Law constant of 1.33X10-5 atm-cu m/mole. Diacetyl may volatilize from dry soil surfaces based upon its vapor pressure. A bacterium that was isolated from Amsterdam harbor water using 2-butanol and tentatively identified as a Pseudomonas was able to degrade diacetyl. Diacetyl was identified as an intermediate in the microbial oxidation of 2-butanol. Since 2-butanol is biodegradable using river water or sewage inoculums with extensive mineralization, biodegradation of diactyl may be an environmental process in soil and water. If released into water, diacetyl is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 1.7 days and 22 days, respectively. An estimated BCF of 3 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions (pH 5 to 9). Occupational exposure to diacetyl may occur through inhalation and dermal contact with this compound at workplaces where diacetyl is produced or used; inhalation of diacetyl has been shown to cause respiratory problems in microwave popcorn plant workers. Monitoring and use data indicate that the general population may be exposed to diacetyl via inhalation of butter flavoring vapors, ingestion of food and drinking water, the use of tobacco products and e-cigarettes, and dermal contact with this compound products containing diacetyl. (SRC)

Diacetyl is found in butter, bay oil and other oils(1); plant volatiles, forest fires, animal wastes(2); tree ripened whole nectarine(3); kiwi fruit flower(4); and as a natural product of fermentation(5).

Diacetyl has been identified in the following plants: Monodora grandiflora Benth, Magnolia tripetale L, Ximenia aegyptiaca L, Petasites fragrans Presl, various narcissi and tulips. Diacetyl has been identified in types of wine, natural aromas of raspberry and strawberry, and oils of lavender, lavandin, reunion geranium and java citronella. Diacetly has been reported in oils of: finnish pine, angelica, and lavender; in flower of Polyalthia canangioides Boerl variety angustifolia and Fagroea racemosa Jack(1).

Diacetyl's production and use as a synthetic flavoring substance and carrier of aroma of butter, vinegar, coffee and other foods(1-3) and use in e-cigarette flavorings(4)may result in its release to the environment through various waste streams(SRC). Emissions from foliar fuels(5) may also contribute to its direct release into the environment(SRC). Diacetyl has been identified as a component of tobacco smoke(2).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 1(SRC), determined from a structure estimation method(2), indicates that diacetyl is expected to have very high mobility in soil(SRC). Volatilization of diacetyl from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 1.33X10-5 atm-cu m/mole(3). Diacetyl is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 56.8 mm Hg at 25 °C(4). A bacterium that was isolated from Amsterdam harbor water using 2-butanol and tentatively identified as a Pseudomonas was able to degrade diacetyl(5). Diacetyl was identified as an intermediate in the microbial oxidation of 2-butanol(5). Since 2-butanol is biodegradable using river water or sewage inoculums with extensive mineralization(6-9), biodegradation of diacetyl may be an environmental process in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 1(SRC), determined from a structure estimation method(2), indicates that diacetyl is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon a Henry's Law constant of 1.33X10-5 atm-cu m/mole(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 1.7 days and 22 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 3(SRC),from its log Kow of -1.34(6) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low. A bacterium that was isolated from Amsterdam harbor water using 2-butanol and tentatively identified as a Pseudomonas was able to degrade diacetyl(7). Diacetyl was identified as an intermediate in the microbial oxidation of 2-butanol(7). Since 2-butanol is biodegradable using river water or sewage inoculums with extensive mineralization(8-11), biodegradation of diacetyl may be an environmental fate process in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), diacetyl, which has a vapor pressure of 56.3 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase diacetyl is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 67 days(SRC), calculated from its rate constant of 2.38X10-13 cu cm/molecule-sec at 25 °C(3). Diacetyl contains chromophores that absorb at wavelengths >290 nm(4) and, therefore, may be susceptible to direct photolysis by sunlight(SRC). The direct photolysis half-life of diacetyl in the atmosphere has been reported at 0.7 hr(5).

AEROBIC: A bacterium that was isolated from Amsterdam harbor water using 2-butanol and tentatively identified as a Pseudomonas was able to degrade diacetyl(1). Diacetyl was identified as an intermediate in the microbial oxidation of 2-butanol(1). Since 2-butanol is biodegradable using river water or sewage inoculums with extensive mineralization(2-5), it is plausible for diacetyl to be biodegradable(SRC).

The rate constant for the vapor-phase reaction of diacetyl with photochemically-produced hydroxyl radicals is 2.38X10-13 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 67 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(2). Diacetyl is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). Diacetyl contains chromophores that absorb at wavelengths >290 nm(3) and, therefore, may be susceptible to direct photolysis by sunlight(SRC). The direct photolysis half-life of diacetyl in the atmosphere has been reported at 0.7 hr(4).

An estimated BCF of 3 was calculated in fish for diacetyl(SRC), using a log Kow of -1.34(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Koc of diacetyl is estimated as 1(SRC), using a log Kow of -1.34(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that diacetyl is expected to have very mobility in soil.

The Henry's Law constant for diacetyl is 1.33X10-5 atm-cu m/mole(1). This Henry's Law constant indicates that diacetyl is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 2.7 days(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 22 days(SRC). Diacetyl's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Diacetyl is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 56.8 mm Hg(3).

DRINKING WATER: Diacetyl was identified as a ozone disinfection by-product in drinking water(1). Diacetyl has been identified in drinking water(2). Diacetyl was detected, not quantified, in 6 of 14 drinking water supplies in England from June 1978 to June 1979(3).

SURFACE WATER: Diacetyl was identified in raw water at 80 ng/L in Boussy Saint Antoine, France in December 1985(1).

Average on-road diacetyl emissions from 7 vehicles was 0.044 mg/km(1). Diesel powered medium duty truck emissions were 900 ug/km(2). Emissions of diacetyl from catalytic and non-catalytic equipped gas-powered tail pipe exhaust was 40 and 1800 ug/km, respectively(3). Diacetyl was measured in the emissions of burned wood at 89, 73, and 73 mg/kg of pine, oak, and eucalyptus, respectively(4). Diacetyl was measured in the emissions of burned wood at 61.2, 67.4 and 280.1 mg/kg from loblolly pine, western hemlock and ponderosa pine, respectively(5). Diacetyl was also found in the emissions of burned mixed hardwood forest foliage, Florida palmetto/slash pine, and wire grass/longleaf pine at 51.3, 90.9 and 233.4 mg/kg of burnt material, respectively(5). Diacetyl was found in the emissions from garden waste(6) and as a component of volatile gases in the headspace of waste in garbage rucks(7). Emissions of diacetyl from cooked hamburger meat over natural gas grill was 28,000 ug/kg of meat(8). Emission factors for light-duty vehicles of diacetyl measured in the Caldecott Tunnel in 1999, 2001, and 2006 were reported as 0.18, 0.14, and 0.14 mg/kg, respectively(9). Emission factors for medium and heavy-duty diesel trucks of diacetyl measured in the Caldecott Tunnel in 2006 was reported at 1.2 mg/kg(9).

Diacetyl has been measured in canned cream corn (5 ppb), canned corn (5 ppb), frozen corn (<2 ppb) and fresh corn (<2 ppb)(1). Diacetyl was found in popcorn using wet extraction method at 170 ug/kg(2). Diacetyl mean concentration of 4 blends of home brewed coffee and 8 blends of instant coffee were 19 and 26 ug/g, respectively(3). Diacetyl was identified in beer(4), roasted earth almonds (Cyperus esculentus l.)(5), dry-cured ham(6), roasted filberts(7), and cooked beef(8). Diacetyl was found in tree ripened whole nectarine(9). Diacetyl was identified in autooxidised sesame, and safflower(10).

Diacetyl was found in tree ripened whole nectarine(1) and as a volatile constituent of kiwi fruit flower(2).

Diactyl occurrence in plants(1).[Table#991]

Diacetyl was found in Charybdis feriatus crabs at 95.7 ug/kg, 129 ug/kg, and 563.2 ug/kg in the leg, body and carapace, respectively(1). Diacetyl was measured at 512 ng/g, 260 ng/g, 2470 ng/g and 791 ng/g in anchovy paste (Engraulis japonica), big eyed herring paste (Harengula zunasi), hair tail viscera paste (Trichiurus japonica) and shrimp paste (Acetes chinensis), respectively(2), and in cooked mussels (Mytilus edulis)(3).

Diacetyl was found in raw chicken breast muscle(1).

Diacetyl was identified in Kefir culture(1), cream culture(1) and milk(2).

Diacetyl has been found in tobacco smoke(1,2). Gas-phase emissions from open burning of six fine (foliar) fuels, loblolly pine, western hemlock, ponderosa pine, mixed hardwood forest foliage litter, Florida palmetto/slash pine, and wiregrass/longleaf pine, contained diacetyl at rates of 61.2, 67.4, 280.1, 51.3, 90.9, and 233.4 mg/kg of biomass burned, respectively(3).

... Diacetyl was detected above the laboratory limit of detection in 39 of the 51 /e-cigarette/ flavors tested, ranging from below the limit of quantification to 239 ug/e-cigarette. ...

NIOSH (NOES Survey 1981-1983) has statistically estimated that 3,438 workers (1,628 of these are female) are potentially exposed to diacetyl in the US(1). Occupational exposure to diacetyl may occur through inhalation and dermal contact with this compound at workplaces where diacetyl is produced or used(SRC). Monitoring and use data indicate that the general population may be exposed to diacetyl via inhalation of butter flavoring vapors, ingestion of food and drinking water, the use of tobacco products, and dermal contact with this compound and other consumer products containing diacetyl(SRC).

Inhalation of diacetyl has been shown to cause respiratory problems in microwave popcorn plant workers(1). Among these workers, exposure to butter flavorings has been associated with fixed obstructive lung disease resembling bronchiolitis obliterans(2).

BACKGROUND: There are > 7,000 e-cigarette flavors currently marketed. Flavoring chemicals gained notoriety in the early 2000s when inhalation exposure of the flavoring chemical diacetyl was found to be associated with a disease that became known as "popcorn lung." There has been limited research on flavoring chemicals in e-cigarettes. OBJECTIVE: We aimed to determine if the flavoring chemical diacetyl and two other high-priority flavoring chemicals, 2,3-pentanedione and acetoin, are present in a convenience sample of flavored e-cigarettes. METHODS: We selected 51 types of flavored e-cigarettes sold by leading e-cigarette brands and flavors we deemed were appealing to youth. E-cigarette contents were fully discharged and the air stream was captured and analyzed for total mass of diacetyl, 2,3-pentanedione, and acetoin, according to OSHA method 1012. RESULTS: At least one flavoring chemical was detected in 47 of 51 unique flavors tested. Diacetyl was detected above the laboratory limit of detection in 39 of the 51 flavors tested, ranging from below the limit of quantification to 239 ug/e-cigarette. 2,3-Pentanedione and acetoin were detected in 23 and 46 of the 51 flavors tested at concentrations up to 64 and 529 ug/e-cigarette, respectively. CONCLUSION: Because of the associations between diacetyl and bronchiolitis obliterans and other severe respiratory diseases observed in workers, urgent action is recommended to further evaluate this potentially widespread exposure via flavored e-cigarettes.

SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

Product: Burn in a chemical incinerator equipped with an afterburner and scrubber but exert extra care in igniting as this material is highly flammable. Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this material. Contaminated packaging: Dispose of as unused product.

Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed.

/GUIDE 127 FLAMMABLE LIQUIDS (Polar/Water-Miscible)/ Fire or Explosion: HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.

/GUIDE 127 FLAMMABLE LIQUIDS (Polar/Water-Miscible)/ Health: Inhalation or contact with material may irritate or burn skin and eyes. Fire may produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control may cause pollution.

/GUIDE 127 FLAMMABLE LIQUIDS (Polar/Water-Miscible)/ Public Safety: CALL Emergency Response Telephone Number on Shipping Paper first. If Shipping Paper not available or no answer, refer to appropriate telephone number listed on the inside back cover. As an immediate precautionary measure, isolate spill or leak area for at least 50 meters (150 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate closed spaces before entering.

/GUIDE 127 FLAMMABLE LIQUIDS (Polar/Water-Miscible)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection.

For more DOT Emergency Guidelines (Complete) data for DIACETYL (8 total), please visit the HSDB record page.

UN 2346; Butanedione

IMO 3; Butanedione

49 091 44; Diacetyl

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials. Butanedione is included on the dangerous goods list.

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article. Butanedione is included on the dangerous goods list.

Must be labeled "Flammable Liquid." It falls in Hazard Class 3 and Packing Group II.

Flammable Liquid

UN Hazard Class: 3; UN Pack Group: II