paraldehyde

H226: Flammable liquid and vapor [Warning Flammable liquids]

P210, P233, P240, P241, P242, P243, P280, P303+P361+P353, P370+P378, P403+P235, and P501 (click each P-code to see the statement)

This chemical does not meet GHS hazard criteria for < 0.1% (1 of 1566) of reports.

H226 (> 99.9%): Flammable liquid and vapor [Warning Flammable liquids]

Aggregated GHS information provided per 1566 reports by companies from 6 notifications to the ECHA C&L Inventory.

Reported as not meeting GHS hazard criteria per 1 of 1566 reports by companies.

There are 5 notifications provided by 1565 of 1566 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.

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

H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]

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]

P210, P233, P240, P241, P242, P243, P260, P264, P264+P265, P270, P280, P302+P352, P303+P361+P353, P305+P351+P338, P308+P316, P319, P321, P332+P317, P337+P317, P362+P364, P370+P378, P403+P235, P405, and P501 (click each P-code to see the statement)

Fresh air, rest. Refer for medical attention.

Remove contaminated clothes. Rinse and then wash skin with water and soap.

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

Do NOT induce vomiting. Give one or two glasses of water to drink. Refer for medical attention .

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. 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. Be prepared to transport the victim to a hospital if advised by a physician. 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 129 [Flammable Liquids (Water-Miscible / Noxious)]:

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

SMALL FIRE: Dry chemical, CO2, water spray or alcohol-resistant foam. Do not use dry chemical extinguishers to control fires involving nitromethane (UN1261) or nitroethane (UN2842).

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

Use water spray, dry chemical, "alcohol resistant" foam, or carbon dioxide. Water may be ineffective. Use water spray to keep fire exposed containers cool. Approach fire from upwind to avoid hazardous vapors and toxic decomposition products.

If material is on fire or involved in a fire: Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Solid streams of water may spread fire. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use "alcohol" foam, dry chemical or carbon dioxide.

Vapors are heavier than air and may travel to a source of ignition and flash back.

· 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 129 [Flammable Liquids (Water-Miscible / Noxious)]:

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. Collect leaking and spilled liquid in sealable non-plastic containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

A good candidate for liquid injection incineration at a temperature range of 650 to 1,600 °C and a residence time of 0.1 to 2 seconds. A good candidate for rotary kiln incineration at a temperature range of 820 to 1,600 °C and residence times of seconds for liquids and gases, and hours for solids. A good candidate for fluidized bed incineration at a temperature range of 450 to 980 °C and residence times of seconds for liquids and gases, and longer for solids.

If material is not on fire and not involved in a fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Attempt to stop leak if without undue personnel hazard. Use water spray to disperse vapors and dilute standing pools of liquid.

Personnel protection: Avoid breathing vapors. Keep upwind. Avoid bodily contact with the material. ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protectionequipment should be worn even when contact lenses are in place.

Excerpt from ERG Guide 129 [Flammable Liquids (Water-Miscible / Noxious)]:

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. Separated from food and feedstuffs, bases and oxidants.

PARALDEHYDE SHOULD BE STORED IN WELL-FILLED, TIGHT, LIGHT-RESISTANT GLASS CONTAINERS WITH A CAPACITY OF NO MORE THAN 30 ML, AT A TEMP NOT EXCEEDING 25 °C.

Store in a cool, dry, well ventilated location. Separate from alkalies, acids, iodides, oxidizing material, rubber, and plastic. Inside storage should be in a standard flammable liquids storage warehouse, room, or cabinet.

IT IS BEST STORED IN 2- OR 5-ML AMPULES, WHICH CAN BE OPENED FRESHLY & UNUSED CONTENTS DISCARDED.

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

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

2.6 [ppm]

29 [ppm]

170 [ppm]

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

Small Fire

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

· Do not use dry chemical extinguishers to control fires involving nitromethane (UN1261) or nitroethane (UN2842).

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 irritating to the eyes, skin and respiratory tract. The substance may cause effects on the central nervous system.

The substance may have effects on the nervous system. This may result in addiction. The substance may have effects on the kidneys and liver. This may result in impaired functions.

Wear rubber gloves, self-contained breathing apparatus. (USCG, 1999)

Personal protective equipment: wear rubber gloves, self-contained breathing apparatus.

Wear appropriate chemical protective gloves, boots, and goggles.

NO open flames, NO sparks and NO smoking. Above 24 °C use a closed system, ventilation and explosion-proof electrical equipment.

Use ventilation, local exhaust or breathing protection.

Protective gloves.

Wear safety spectacles or eye protection in combination with breathing protection.

Do not eat, drink, or smoke during work.

Paraldehyde appears as a clear colorless liquid with a pleasant odor. Flash point 96 °F. Melting point 54 °F. Less dense than water. Vapors are heavier than air.

Colorless liquid with a pleasant odor; Decomposes on standing; Soluble in water; [Hawley]

COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR.

COLORLESS, TRANSPARENT LIQUID

CHARACTERISTIC AROMATIC ODOR

Agreeable odor

DISAGREEABLE TASTE

Burning taste

262 °F at 760 mmHg (NTP, 1992)

124.5 °C

123.00 to 124.00 °C. @ 760.00 mm Hg

124.3 °C @760 [mm Hg]

54.7 °F (NTP, 1992)

96 °F (NTP, 1992)

96 °F (OPEN CUP)

24 °C c.c.

Sparingly soluble (NTP, 1992)

SOL IN 8 PARTS WATER AT 25 °C; 17 PARTS BOILING WATER

Sol in water: 1 in 9 parts at 20 °C, 1 in 10 parts at 30 °C, & 1 in 11.5 parts at 37 °C

Sol in sodium chloride solution: 1 in 9.5 parts at 20 °C, 1 in 11 parts at 30 °C, & 1 in 12.5 parts at 37 °C

MISCIBLE WITH ALC, CHLOROFORM, ETHER, OILS

water solubility = 12g/100 g water at 13 degC

112 mg/mL at 30 °C

Solubility in water, g/100ml at 13 °C: 12

0.9943 at 68 °F (USCG, 1999) - Less dense than water; will float

0.9923 @ 20 °C/4 °C

SPECIFIC HEAT 0.434; BULK DENSITY 8.27 LB/GAL (20 °C)

0.99 g/cm³

0.9943 @ 20°C

Relative vapor density (air = 1): 4.5

11.0 [mmHg]

25.3 mm Hg at 20 °C

Vapor pressure, kPa at 20 °C: 1

7.5 [mm Hg] @17 °C

Log Kow = 0.67

ON EXPOSURE TO LIGHT & AIR, IT DECOMP TO ACETALDEHYDE & IS OXIDIZED TO ACETIC ACID

DECOMPOSES ON STANDING, STABLE TOWARD ALKALIES.

Preparations of paraldehyde that have a brownish color or a sharp penetrating odor of acetic acid should not be used.

460 °F (USCG, 1999)

1.128 centipoise at 70 °F

Highly flammable. Slightly soluble in water. Decomposed by light and air, on prolonged storage, to acetaldehyde and acetic acid.

Highly Flammable

PARALDEHYDE is an ether derivative. This compound is decomposed by light and air, on prolonged storage, to acetaldehyde and acetic acid. Incompatible with alkalis, hydrocyanic acid iodides and oxidizers. (NTP, 1992)

Paraldehyde is incompatible with many plastics

INCOMPATIBILITIES: ACIDS CONVERT PARALDEHYDE INTO ACETALDEHYDE, WHICH IS PRONE TO OXIDATION.

INCOMPATIBILITIES: ALKALIES, HYDROCYANIC ACID, IODIDES, OXIDIZERS.

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

Burning sensation. Cough. Shortness of breath. Further see Ingestion.

Redness. Pain.

Burning sensation in the throat and chest. Nausea. Vomiting. Diarrhoea. Drowsiness. Unconsciousness.

Neurotoxin - Other CNS neurotoxin

Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.

LCLo (rat) = 4,000 ppm/4h

LD50 Dog oral (acute) 3.0 to 4.0 g/kg

Animal studies indicate that disulfiram slows the metabolism of paraldehyde by way of inhibition of acetaldehyde dehydrogenase resulting in an increase in blood concn of paraldehyde & acetaldehyde. Until this potential interaction is investigated in humans, paraldehyde & disulfiram should be admin together with caution.

INTERACTIONS BETWEEN PARALDEHYDE & ETHYL ALCOHOL ARE NOT WELL UNDERSTOOD ... DOSES OF 1-2 OZ IN ALCOHOLICS SOMETIMES KILL WITHIN 0.5-4 HR. IN ANIMALS ETHANOL & PARALDEHYDE ARE SYNERGISTIC BUT LESS THAN ADDITIVE IN TERMS OF LETHALITY; UNDER SOME DOSAGE SCHEDULES, HOWEVER, EXPTL DATA SUGGEST THAT THESE DRUGS ARE ANTAGONISTIC.

ADDITIVE CNS DEPRESSION MAY OCCUR WHEN PARALDEHYDE IS ADMIN CONCOMITANTLY WITH OTHER CNS DEPRESSANTS SUCH AS BARBITURATES OR ALCOHOL. SOME FATALITIES HAVE BEEN ASSOCIATED WITH CONCOMITANT USE OF ALCOHOL & PARALDEHYDE.

The increased acetate levels which may follow paraldehyde administration reportedly may increase the danger of sulfonamide crystalluria.

For more Interactions (Complete) data for PARALDEHYDE (7 total), please visit the HSDB record page.

Treatment is directed toward maintenance of airway, breathing, and circulation. Supportive care is the mainstay of therapy. Patients are often critically ill and must be under constant supervision.

... IT MAY PRODUCE EXCITEMENT OR DELIRIUM IN PRESENCE OF PAIN. ... IN LARGE DOSES, IT PRODUCES RESPIRATORY DEPRESSION & HYPOTENSION.

SOME DELAY IN ONSET OF RESP MOVEMENTS HAS BEEN OBSERVED IN NEONATES FOLLOWING ITS ADMIN TO MOTHER DURING LABOR.

Patients poisoned by paraldehyde commonly exhibit very rapid, labored respiratory movements. Acidosis, bleeding gastritis, muscular irritability, azotemia, oliguria, albuminuria, leukocytosis, fatty changes in the liver and kidney with toxic hepatitis and nephrosis, pulmonary hemorrhages and edema, and dilatation of the right ventricle have all been observed in cases of severe acute or chronic paraldehyde poisoning.

Chronic paraldehyde intoxication results in tolerance and dependence. The paraldehyde addict may become acquainted with the drug when it is used in the treatment of alcoholism and then, surprisingly in view of its disagreeable taste and odor, prefer it to alcohol. Paraldehyde addiction resembles alcoholism, and sudden withdrawal may result in delirium tremens and vivid hallucinations.

For more Human Toxicity Excerpts (Complete) data for PARALDEHYDE (18 total), please visit the HSDB record page.

PARALDEHYDE HAS BEEN TESTED FOR INFLUENCE ON INTRAOCULAR PRESSURE WHEN ADMIN SYSTEMICALLY TO DOGS & TO NORMAL & GLAUCOMATOUS RABBITS, & WAS FOUND TO CAUSE NO ELEVATION, POSSIBLY SLIGHT REDN OF PRESSURE.

Paraldehyde may be released to the environment in emissions or effluents from sites of its manufacture or industrial use (paraldehyde is used as a drug, chemical intermediate, dyestuff intermediate, and solvent) and from disposal of wastes containing this compound (ie hospital wastes). If released to soil surfaces, paraldehyde may volatilize rapidly or it may leach into deeper soil. Potential degradation products include acetaldehyde and acetic acid. If released to water, volatilization is expected to be an imporant, if not the dominant, fate process (half-life in a model river 31 hr). If released to the atmosphere, reaction with photochemically generated hydroxyl radicals is expected to be the dominant removal mechanism (half-life 45 hr). This compound may also be removed from the atmosphere in precipitation. The general population may be exposed to paraldehyde by ingestion of cooked meat which contains this compound (eg bacon) or intentional use of this cmpd as a drug. (SRC)

Paraldehyde may be released to the environment in emissions or effluents from sites of its manufacture or industrial use (paraldehyde is used as a drug, chemical intermediate, dyestuff intermediate, and solvent(1)) and from disposal of wastes containing this compound (ie hospital wastes)(2,3,SRC).

TERRESTRIAL FATE: If released to soil, paraldehyde may volatilize rapidly from soil surfaces or it may leach into deeper soil. Potential degradation products include acetaldehyde and acetic acid. (SRC)

AQUATIC FATE: If released to water, volatilization is expected to be an important, if not the dominant, fate process (half-life in a model river: 31 hr). Paraldehyde is not expected to bioaccumulate in aquatic organisms, or adsorb to suspended solids and sediments in water. (SRC)

ATMOSPHERIC FATE: Based on a vapor pressure of 25.5 mm Hg at 20 °C(1), paraldehyde is expected to exist almost entirely in the vapor phase in the atmosphere(2,SRC). Reaction with photochemically generated hydroxyl radicals is expected to be the dominant removal mechanism (half-life 45 hours). The relatively high water solubility of paraldehyde (125,000 mg/l at 25 °C(3)) suggests that this compound may also be removed from the atmosphere in precipitation(SRC).

Japanese MITI, initial concn 100 ppm, 14 days <30% BODT, activated sludge inoculum(1). A bacterium isolated from sewage, C. paraldehydium KY 4359, was found to degrade paraldehyde to acetaldehyde and acetic acid(2).

Paraldehyde decomposes on standing(1). This compound is stable to alkalies but slowly decomposes to acetaldehyde when treated with mineral acid(1). The half-life for paraldehyde reacting with photochemically generated hydroxyl radicals in natural water has been estimated to be >2 years based on a measured reaction rate constants of 6.0X10+8 and 1.0X10+9 l/mole-sec and an ambient hydroxyl radical concentration of 1X10-17 mol/l(2,3,4,SRC). The half-life for paraldehyde vapor reacting with photochemically generated hydroxyl radicals in the atmosphere has been estimated to be 45 hours based on an estimated reaction rate constant of 8.5X10-12 cu cm/molecules-sec at 25 °C and an average ambient hydroxyl concentration of 5X10+5 molecules/cu cm(5,SRC).

Based on a water solubility of 125,000 mg/l at 25 °C and a log Kow of 0.67, bioconcentration factors (BCF) of 0.8-2 were estimated for paraldehyde(1,2,3,SRC). These BCF values suggest that paraldehyde would not bioaccumulate significantly in aquatic organisms(SRC).

Soil adsorption coefficients (Koc) of 7-55 were estimated for paraldehyde using linear regression equations based on a water solubility of 125,000 mg/l at 25 °C and a log Kow of 0.67(1,2,3,SRC). These Koc values suggest that paraldehyde would be very highly mobile in soil and that adsorption to suspended solids and sediments in water would be insignificant(4,SRC).

Henry's Law Constant for paraldehyde has been estimated to be on the order of 4X10-5 atm-cu m/mole based on a water solubility of 125,000 mg/l at 25 °C and a vapor pressure of 25.5 mm Hg at 20 °C(1,2,SRC). This value of Henry's Law Constant suggests that paraldehyde would volatilize fairly rapidly from all bodies of water and from moist soil surfaces(3,SRC). Based on this value the volatilization half-life of paraldehyde from a model river 1 m deep flowing 1 m/sec with a wind velocity of 3 m/sec has been estimated to be 31 hr(3,SRC). The relatively high vapor pressure of paraldehyde suggests that this compound would volatilize rapidly from dry soil surfaces(2,SRC).

Identified in the effluent from a publicly owned treatment works in the USA(1). Identified in leachate samples taken from low-level radioactive waste disposal sites in Maxy Flats, KY and West Valley, NY(2).

Identified as a volatile flavor component of fried bacon(1).

Identified as a volatile component of hydrated collagen heated at normal roasting temperatures(1). Although this is not the same as actually roasting fresh meat, this suggests that paraldehyde may be present in cooked meat(1).

The general population may be exposed to paraldehyde by ingestion of cooked meat which contains this compound (eg bacon)(1,2,SRC). Small segments of the general population may be exposed to paraldehyde as a result of its intentional use as a hypnotic drug(3,SRC).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 1,728 workers are potentially exposed to paraldehyde in the USA(1).

Paraldehyde may be released to the environment in emissions or effluents from sites of its manufacture or industrial use (paraldehyde is used as a drug, chemical intermediate, dyestuff intermediate, and solvent) and from disposal of wastes containing this compound (ie hospital wastes). If released to soil surfaces, paraldehyde may volatilize rapidly or it may leach into deeper soil. Potential degradation products include acetaldehyde and acetic acid. If released to water, volatilization is expected to be an imporant, if not the dominant, fate process (half-life in a model river 31 hr). If released to the atmosphere, reaction with photochemically generated hydroxyl radicals is expected to be the dominant removal mechanism (half-life 45 hr). This compound may also be removed from the atmosphere in precipitation. The general population may be exposed to paraldehyde by ingestion of cooked meat which contains this compound (eg bacon) or intentional use of this cmpd as a drug. (SRC)

Paraldehyde may be released to the environment in emissions or effluents from sites of its manufacture or industrial use (paraldehyde is used as a drug, chemical intermediate, dyestuff intermediate, and solvent(1)) and from disposal of wastes containing this compound (ie hospital wastes)(2,3,SRC).

TERRESTRIAL FATE: If released to soil, paraldehyde may volatilize rapidly from soil surfaces or it may leach into deeper soil. Potential degradation products include acetaldehyde and acetic acid. (SRC)

AQUATIC FATE: If released to water, volatilization is expected to be an important, if not the dominant, fate process (half-life in a model river: 31 hr). Paraldehyde is not expected to bioaccumulate in aquatic organisms, or adsorb to suspended solids and sediments in water. (SRC)

ATMOSPHERIC FATE: Based on a vapor pressure of 25.5 mm Hg at 20 °C(1), paraldehyde is expected to exist almost entirely in the vapor phase in the atmosphere(2,SRC). Reaction with photochemically generated hydroxyl radicals is expected to be the dominant removal mechanism (half-life 45 hours). The relatively high water solubility of paraldehyde (125,000 mg/l at 25 °C(3)) suggests that this compound may also be removed from the atmosphere in precipitation(SRC).

Japanese MITI, initial concn 100 ppm, 14 days <30% BODT, activated sludge inoculum(1). A bacterium isolated from sewage, C. paraldehydium KY 4359, was found to degrade paraldehyde to acetaldehyde and acetic acid(2).

Paraldehyde decomposes on standing(1). This compound is stable to alkalies but slowly decomposes to acetaldehyde when treated with mineral acid(1). The half-life for paraldehyde reacting with photochemically generated hydroxyl radicals in natural water has been estimated to be >2 years based on a measured reaction rate constants of 6.0X10+8 and 1.0X10+9 l/mole-sec and an ambient hydroxyl radical concentration of 1X10-17 mol/l(2,3,4,SRC). The half-life for paraldehyde vapor reacting with photochemically generated hydroxyl radicals in the atmosphere has been estimated to be 45 hours based on an estimated reaction rate constant of 8.5X10-12 cu cm/molecules-sec at 25 °C and an average ambient hydroxyl concentration of 5X10+5 molecules/cu cm(5,SRC).

Based on a water solubility of 125,000 mg/l at 25 °C and a log Kow of 0.67, bioconcentration factors (BCF) of 0.8-2 were estimated for paraldehyde(1,2,3,SRC). These BCF values suggest that paraldehyde would not bioaccumulate significantly in aquatic organisms(SRC).

Soil adsorption coefficients (Koc) of 7-55 were estimated for paraldehyde using linear regression equations based on a water solubility of 125,000 mg/l at 25 °C and a log Kow of 0.67(1,2,3,SRC). These Koc values suggest that paraldehyde would be very highly mobile in soil and that adsorption to suspended solids and sediments in water would be insignificant(4,SRC).

Henry's Law Constant for paraldehyde has been estimated to be on the order of 4X10-5 atm-cu m/mole based on a water solubility of 125,000 mg/l at 25 °C and a vapor pressure of 25.5 mm Hg at 20 °C(1,2,SRC). This value of Henry's Law Constant suggests that paraldehyde would volatilize fairly rapidly from all bodies of water and from moist soil surfaces(3,SRC). Based on this value the volatilization half-life of paraldehyde from a model river 1 m deep flowing 1 m/sec with a wind velocity of 3 m/sec has been estimated to be 31 hr(3,SRC). The relatively high vapor pressure of paraldehyde suggests that this compound would volatilize rapidly from dry soil surfaces(2,SRC).

Identified in the effluent from a publicly owned treatment works in the USA(1). Identified in leachate samples taken from low-level radioactive waste disposal sites in Maxy Flats, KY and West Valley, NY(2).

Identified as a volatile flavor component of fried bacon(1).

Identified as a volatile component of hydrated collagen heated at normal roasting temperatures(1). Although this is not the same as actually roasting fresh meat, this suggests that paraldehyde may be present in cooked meat(1).

The general population may be exposed to paraldehyde by ingestion of cooked meat which contains this compound (eg bacon)(1,2,SRC). Small segments of the general population may be exposed to paraldehyde as a result of its intentional use as a hypnotic drug(3,SRC).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 1,728 workers are potentially exposed to paraldehyde in the USA(1).

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

A good candidate for liquid injection incineration at a temperature range of 650 to 1,600 °C and a residence time of 0.1 to 2 seconds. A good candidate for rotary kiln incineration at a temperature range of 820 to 1,600 °C and residence times of seconds for liquids and gases, and hours for solids. A good candidate for fluidized bed incineration at a temperature range of 450 to 980 °C and residence times of seconds for liquids and gases, and longer for solids.

/GUIDE 129: FLAMMABLE LIQUIDS (Polar/Water-Miscible/Noxious)/ 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 129: FLAMMABLE LIQUIDS (Polar/Water-Miscible/Noxious)/ Health: May cause toxic effects if inhaled or absorbed through skin. Inhalation or contact with material may irritate or burn skin and eyes. Fire will produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution.

/GUIDE 129: FLAMMABLE LIQUIDS (Polar/Water-Miscible/Noxious)/ 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 129: FLAMMABLE LIQUIDS (Polar/Water-Miscible/Noxious)/ 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 PARALDEHYDE (8 total), please visit the HSDB record page.

UN 1264; Paraldehyde

IMO 3.3; Paraldehyde

49 092 60; Paraldehyde

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.

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.

Flammable Liquid

Do not transport with food and feedstuffs.

Symbol: F; R: 11; S: (2)-9-16-29-33

UN Hazard Class: 3; UN Pack Group: III