Cyclopentadiene

H225 (28.2%): Highly Flammable liquid and vapor [Danger Flammable liquids]

H226 (71.8%): Flammable liquid and vapor [Warning Flammable liquids]

H301+H311 (28%): Toxic if swallowed or in contact with skin [Danger Acute toxicity, oral; acute toxicity, dermal]

H301 (92.2%): Toxic if swallowed [Danger Acute toxicity, oral]

H311 (29.6%): Toxic in contact with skin [Danger Acute toxicity, dermal]

H312 (62.6%): Harmful in contact with skin [Warning Acute toxicity, dermal]

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

H319 (100%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]

H332 (87.6%): 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, P262, P264, P264+P265, P270, P271, P280, P301+P316, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P316, P317, P319, P321, P330, P332+P317, P337+P317, P361+P364, P362+P364, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 372 reports by companies from 9 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

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: Highly Flammable liquid and vapor [Danger Flammable liquids]

H301: Toxic if swallowed [Danger Acute toxicity, oral]

H311: Toxic in contact with skin [Danger Acute toxicity, dermal]

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

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

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

H332: Harmful if inhaled [Warning Acute toxicity, inhalation]

H336: May cause drowsiness or dizziness [Warning Specific target organ toxicity, single exposure; Narcotic effects]

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

H373: 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, P262, P264, P264+P265, P270, P271, P272, P280, P301+P316, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P308+P316, P316, P317, P319, P321, P330, P332+P317, P333+P317, P337+P317, P361+P364, P362+P364, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

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

P210, P233, P240, P241, P242, P243, P260, P261, P262, P264, P264+P265, P270, P271, P280, P301+P316, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P316, P317, P319, P321, P330, P337+P317, P361+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 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.

Rinse mouth. Seek medical attention if you feel unwell.

Excerpt from NIOSH Pocket Guide for Cyclopentadiene:

Eye: IRRIGATE IMMEDIATELY - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: SOAP WASH PROMPTLY - If this chemical contacts the skin, promptly wash the contaminated skin with soap and water. If this chemical penetrates the clothing, promptly remove the clothing and wash the skin with soap and water. Get medical attention promptly.

Breathing: RESPIRATORY SUPPORT - If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform artificial respiration. Keep the affected person warm and at rest. Get medical attention as soon as possible.

Swallow: MEDICAL ATTENTION IMMEDIATELY - If this chemical has been swallowed, get medical attention immediately. (NIOSH, 2024)

(General first aid procedures)

Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: Soap wash promptly - If this chemical contacts the skin, promptly wash the contaminated skin with soap and water. If this chemical penetrates the clothing, promptly remove the clothing and wash the skin with soap and water. Get medical attention promptly.

Breathing: Respiratory support

Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately.

Excerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:

CAUTION: The majority of these products have a very low flash point. Use of water spray when fighting fire may be inefficient. CAUTION: For mixtures containing alcohol or polar solvent, alcohol-resistant foam may be more effective.

SMALL FIRE: Dry chemical, CO2, water spray or regular foam. If regular foam is ineffective or unavailable, use alcohol-resistant foam.

LARGE FIRE: Water spray, fog or regular foam. If regular foam is ineffective or unavailable, use 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. For petroleum crude oil, do not spray water directly into a breached tank car. This can lead to a dangerous boil over. 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, foam, carbon dioxide. In case of fire: keep drums, etc., cool by spraying with water.

Powder, aqueous film-forming foams (AFFF), foam, carbon dioxide ... Keep drums, etc, cool by spraying with water.

Dry chemical, carbon dioxide, foam

The vapor is heavier than air ... A harmful contamination of the air can be reached rather quickly on evaporation of this substance at 20 °C.

Excerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:

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)

Evacuate danger area! Remove all ignition sources. Consult an expert! Personal protection: self-contained breathing apparatus. Collect leaking liquid in sealable containers. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.

Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent and remove to safe place (extra personal protection: self-contained breathing apparatus).

1. Remove ... ignition sources. 2. Ventilate area of spill. ... 3. For small quantity, allow material to dimerize, collect on paper or other material. Evaporate in safe place (such as fume hood). Allow sufficient time for evaporating vapors to completely clear hood ductwork. Burn paper in suitable location. ... 3. Large quantities may be reclaimed or dissolved in appropriate solvent & atomized in suitable combustion chamber. ... Should not be allowed to enter confined space, such as sewer, because of possibility of an explosion.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. 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 soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

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.

Incineration

SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits 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 protection equipment should be worn even when contact lenses are in place.

SRP: Contaminated protective clothing should be segregated in a manner such that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. The completeness of the cleaning procedures should be considered before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at the end of shift, but should remain at employee's place of work for cleaning.

SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants. Ensure that the local ventilation moves the contaminant away from the worker.

The worker should immediately wash the skin when it becomes contaminated.

For more Preventive Measures (Complete) data for 1,3-CYCLOPENTADIENE (7 total), please visit the HSDB record page.

Excerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:

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 only if stabilized. Cooled. Separated from incompatible materials. See Chemical Dangers.

A harmful contamination of the air can be reached rather quickly on evaporation of this substance at 20 °C.

Fireproof. Separated from strong oxidants, strong acids, potassium hydroxide. Cooled. Store only if stabilized.

Monomer may largely be prevented from dimerizing by storage at -80 °C or below.

75 ppm (200 mg/m³)

TWA 75 ppm (200 mg/m3)

75.0 [ppm]

750 ppm (NIOSH, 2024)

750.0 [ppm]

Excerpts from Documentation for IDLHs: Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Deichmann and Gerarde [1969] that 4 of 6 rats died from a 4­hour exposure to 2,000 ppm [Smyth et al. 1954]. . . . Human data: None relevant for use in determining the revised IDLH.

See: 542927

8 hr Time Weighted Avg (TWA): 75 ppm.

Excursion Limit Recommendation: Excursions in worker exposure levels may exceed 3 times the TLV-TWA for no more than a total of 30 minutes during a work day, and under no circumstances should they exceed 5 times the TLV-TWA, provided that the TLV-TWA is not exceeded.

0,5 ppm as TWA

0.5 ppm [2018]

1 ppm [2018]

A harmful contamination of the air can be reached very quickly on evaporation of this substance at 20 °C.

The substance is irritating to the eyes and respiratory tract. The substance is mildly irritating to the skin.

Excerpt from NIOSH Pocket Guide for Cyclopentadiene:

Skin: PREVENT SKIN CONTACT - Wear appropriate personal protective clothing to prevent skin contact.

Eyes: PREVENT EYE CONTACT - Wear appropriate eye protection to prevent eye contact.

Wash skin: WHEN CONTAMINATED - The worker should immediately wash the skin when it becomes contaminated.

Remove: WHEN WET (FLAMMABLE) - Work clothing that becomes wet should be immediately removed due to its flammability hazard (i.e., for liquids with a flash point <100 °F).

Change: No recommendation is made specifying the need for the worker to change clothing after the workshift. (NIOSH, 2024)

Wear appropriate personal protective clothing to prevent skin contact.

Wear appropriate eye protection to prevent eye contact.

Respirator Recommendations: Up to 750 ppm:[Table#3933]

Respirator Recommendations: Emergency or planned entry into unknown concentrations or IDLH conditions:[Table#3934]

For more Personal Protective Equipment (PPE) (Complete) data for 1,3-CYCLOPENTADIENE (6 total), please visit the HSDB record page.

NIOSH/OSHA

Up to 750 ppm:

(APF = 10) Any chemical cartridge respirator with organic vapor cartridge(s)

(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister

(APF = 25) Any powered, air-purifying respirator with organic vapor cartridge(s)

(APF = 10) Any supplied-air respirator

(APF = 50) Any self-contained breathing apparatus with a full facepiece

Emergency or planned entry into unknown concentrations or IDLH conditions:

(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode

(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus

Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

NO open flames, NO sparks and NO smoking. Above 25 °C use a closed system, ventilation and explosion-proof electrical equipment. NO contact with incompatible materials:

PREVENT GENERATION OF MISTS! STRICT HYGIENE!

Use ventilation, local exhaust or breathing protection.

Cyclopentadiene is a colorless liquid with an irritating, terpene-like odor. Bp: 42.5 °C; Flash point: 77 °F. Density: 0.805 g cm-3.

Colorless liquid with an irritating, terpene-like odor; [NIOSH]

COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR.

Colorless liquid with an irritating, terpene-like odor.

Colorless liquid

MONOMERIC FORM HAS TERPENE ODOR IN VAPOR STATE

Irritating terpene-like odor

107 °F at 760 mmHg (NIOSH, 2024)

41.5-42.0 °C

-121 °F (NIOSH, 2024)

-95.54 °C

77 °F (NIOSH, 2024)

77 °F (OPEN CUP)

77 °F (open cup)

(oc) 77 °F

Insoluble (NIOSH, 2024)

In water, 1,800 mg/L at 25 °C

Miscible with carbon tetrachloride; soluble in carbon disulfide, aniline, acetic acid, liquid petrolatum

Soluble in acetone; miscible with ethanol, ethyl ether, benzene

Solubility in water: insoluble

Insoluble

0.8 (NIOSH, 2024) - Less dense than water; will float

0.8021 g/cu cm at 20 °C

Relative density (water = 1): 0.8

(AIR= 1) AT BOILING POINT OF CYCLOPENTADIENE 2.3

Relative vapor density (air = 1): 2.3

400 mmHg (NIOSH, 2024)

435.0 [mmHg]

Vapor pressure, kPa at 20 °C: 45.1 (calculated)

400 mmHg

When heated to decomposition it emits acrid smoke and irritating fumes.

It decomposes violently at high temperatures and pressures.

The substance will readily polymerize to dimer with fire or explosion hazard. The reaction is accelerated by peroxides or trichloroacetic acid.

Dimerization is highly exothermic, the rate increasing rapidly with temperature, and may cause rupture of a closed uncooled container ... The polymerization of the undiluted diene may become explosive within the range 0 to 40 °C and at pressures up to 340 bar ...

Odor Threshold Low: 1.8 [ppm]

Odor threshold from AIHA

Low Threshold= 5.0 mg/cu m; High threshold= 5.0 mg/cu m.

Index of refraction = 1.4440 at 20 °C/D

Index of refraction: 1.44632 at 16 °C/D

MP: -85 °C. Density: 0.8235 at 0 °C/4 °C; 0.8131 at 10 °C/4 °C; 0.7966 at 25 °C/4 °C; 0.7914 at 30 °C/4 °C

No rapid reaction with air. No rapid reaction with water.

Hydrocarbons, Aliphatic Unsaturated

Conjugated Dienes

Highly Flammable

Explosive

CYCLOPENTADIENE is incompatible with strong oxidizing agents. Ignites on contact with oxygen (O2) and ozone (O3). Explodes on contact with fuming nitric acid or a mixture of sulfuric acid and nitrogen tetroxide. Reacts vigorously on contact with potassium hydroxide and other strong bases. Mixtures with air are explosive. Presents a moderate explosion hazard when exposed to heat or flame. Decomposes violently at high temperature and pressure. May form explosive peroxides in storage. Undergoes a spontaneous dimerization at room temperature to give DICYCLOPENTADIENE (C10H12, CAS No: 77-73-6), which is a low-melting solid (melting point: 32.5 °C). The reaction is strongly exothermic (Hazardous Chemicals Desk Reference, p. 360 (1987)), but occurs sufficiently slowly that cyclopentadiene can be said to be stable at room temperature. The dimerization accounts for the partial or complete solidification of liquid cyclopentadiene in storage. Polymerization occurs more rapidly and extensively at higher temperatures. When heated to 180-200 °C, cyclopentadiene gives polycyclopentadiene, a white waxy solid. Stronger heating breaks down polycyclopentadiene and re-generates the monomeric cyclopentadiene as a vapor. The vapor decomposes violently at higher temperatures and pressures.

Reacts vigorously on contact with potassium hydroxide.

Contact with the ethanolic base /eg potassium hydroxide/ causes vigorously exothermic resin formation.

Incompatible with nitric acid; oxides of nitrogen; oxygen; sulfuric acid.

Dienes and acetylene derivatives are hypergolic on contact with concn nitric acid, ignition delay being 1 ms. Cyclopentadiene reacts explosively with fuming nitric acid, igniting under nitrogen ...

For more Hazardous Reactivities and Incompatibilities (Complete) data for 1,3-CYCLOPENTADIENE (9 total), please visit the HSDB record page.

Strong oxidizers, fuming nitric acid, sulfuric acid [Note: Polymerizes to dicyclopentadiene upon standing.]

IDENTIFICATION AND USE: 1,3-Cyclopentadiene is a colorless liquid with an unpleasant odor. It is used as a starter compound in the manufacturing of resins and in organic synthesis as a starting material for synthetic prostaglandins, chlorinated insecticides, and formation of sandwich compounds by chelation. HUMAN EXPOSURE AND TOXICITY: Human exposure may occur during the manufacturing process. Short term exposure: exposure can irritate the eyes, skin, and respiratory tract. Skin contact causes a burning sensation and rash. Long term exposure: exposure may damage the liver and kidneys. Exposure can cause a skin allergy to develop. If allergy develops, even low exposures may cause symptoms. No further human studies could be located. ANIMAL STUDIES: Exposure to 1,3-Cyclopentadiene vapors produce CNS depression in the frog in 10 minutes, with a complete recovery in 70 minutes. In rats, 35 repeated daily 7-hour exposures to cyclopentadiene during a period of 53 days at an average concentration of 500 ppm resulted in mild injury to both liver and kidneys described as centrilobular, cloudy swelling of liver cells and cloudy vacuolization of renal tubular epithelium. In contrast, repeated daily exposures at 250 ppm produced no effects in rabbits, rats, guinea pigs, and dogs. In rabbits, subcutaneous injection of 3 cc was a CNS depressing dose with fatal convulsions; however, injections of 0.5 to 1.0 cc did not induce CNS depression. Signs and symptoms during CNS depression included primary motor unrest and a decreased intermittent respiration rate prior to death. The liquid caused marked local irritation, exudates in the pleural and peritoneal cavities, and hyperemia of the kidneys.

The substance can be absorbed into the body by inhalation.

inhalation, ingestion, skin and/or eye contact

Cough. Sore throat.

Redness.

Redness. Pain.

Nausea. Vomiting.

irritation eyes, nose

Eyes, respiratory system

Neurotoxin - Acute solvent syndrome

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.

HEAST Current

LC67 (rat) = 2,000 ppm/4H

LC50 Rat inhalation 39 mg/L/1 hr

LC50 Mouse inhalation 15 mg/L/1 hr

An added stabilizer or inhibitor can influence the toxicological properties of this substance.

FIRST AID: Inhalation--Fresh air, rest. Refer for medical attention. Skin--Remove contaminated clothes. Rinse and then wash skin with water and soap. Eyes--First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor. Ingestion--Rinse mouth. Refer for medical attention.

/SRP:/ 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 as 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. /Aromatic hydrocarbons and related compounds/

/SRP:/ 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 ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye 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 ... . /Aromatic hydrocarbons and related compounds/

/SRP:/ 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. Consider drug therapy for pulmonary edema ... . 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 ... .Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Aromatic hydrocarbons and related compounds/

If symptoms develop or overexposure is suspected, the following may be useful: liver and kidney function tests. Evaluation by a a qualified allergist, including careful exposure history and special testing, may help diagnose skin allergy.

/SIGNS AND SYMPTOMS/ Short Term Exposure: Exposure can irritate the eyes, skin, and respiratory tract. Skin contact causes a burning sensation and rash.

/SIGNS AND SYMPTOMS/ Human sensory response was distinctly unfavorable at both 250 and 500 ppm cyclopentadiene in terms of irritating, objectionable odor.

/SIGNS AND SYMPTOMS/ Long Term Exposure: Exposure may damage the liver and kidneys. Exposure can cause a skin allergy to develop. If allergy develops, even low exposures may cause symptoms.

/LABORATORY ANIMALS: Acute Exposure/ /1,3-Cyclopentadiene/ vapors produce CNS depression in the frog in 10 min, but recovery is complete in 70 min.

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ 35 repeated, daily, 7-hour exposures to cyclopentadiene during a period of 53 days at an average concentration of 500 ppm resulted in mild injury to both liver and kidneys of rats (e.g., centrilobular, cloudy swelling of liver cells and cloudy vacuolization of renal tubular epithelium), repeated, daily exposures at 250 ppm for 135 times produced no manifest effects in rabbits, rats, guinea pigs, and dogs. Hematologic effects were noticeably absent.

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ ... Exposures of 39 dogs at 400 ppm for 6 hours, followed by 16 six-hour exposures at double this average concentration produced no ill effects as judged by body weight, sedimentation rates, red and white blood cell counts, liver function tests, serum transaminase activities (serum glutamic-pyruvic transaminase and serum glutamic-oxaloacetic transaminase), electrocardiograms, or gross and microscopic examinations of critical organs.

/LABORATORY ANIMALS: Neurotoxicity/ ... Subcutaneous injection of 3 cc into rabbits was a /CNS depressing/ dose with fatal convulsions; however, injections of 0.5 to 1.0 cc did not induce /CNS depression in/ the animals. Signs and symptoms during /CNS depression/ included primary motor unrest and a decreased, intermittent respiration rate prior to death. The liquid caused marked local irritation, exudates in the pleural and peritoneal cavities, and hyperemia of the kidneys.

1,3-Cyclopentadiene's production and use as a chemical intermediate may result in its release to the environment through various waste streams. If released to air, a vapor pressure of 435 mm Hg at 25 °C indicates 1,3-cyclopentadiene will exist solely as a vapor in the atmosphere. Vapor-phase 1,3-cyclopentadiene will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals and ozone; the half-lives for these reactions in air are estimated to be 2.5 hours and 52 min, respectively. Reaction of 1,3-cyclopentadiene with nitrate radicals in the night time atmosphere may also be a relevant removal mechanism. If released to soil, 1,3-cyclopentadiene is expected to have high mobility based upon an estimated Koc of 80. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 2.1X10-2 atm-cu m/mole. 1,3-Cyclopentadiene may volatilize from dry soil surfaces based upon its vapor pressure. If concentrated solution of 1,3-cyclopentadiene is released to soil or water (spilled), this compound is expected to polymerize spontaneously to dicyclopentadiene. If released into water, 1,3-cyclopentadiene 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 estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 2.4 hours and 3.2 days, respectively. An estimated BCF of 14 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 1,3-cyclopentadiene may occur through inhalation and dermal contact with this compound at workplaces where 1,3-cyclopentadiene is produced or used. Monitoring data indicate that the general population may be exposed to 1,3-cyclopentadiene via inhalation of ambient air, ingestion of contaminated drinking water, and dermal contact. (SRC)

1,3-Cyclopentadiene's production and use as a starting material for synthetic prostaglandins, for chlorinated insecticides, and the formation of sandwich compounds by chelation, for example, cyclopentadienyl iron dicarbonyl dimer(1), may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 80(SRC), determined from a structure estimation method(2), indicates that 1,3-cyclopentadiene is expected to have high mobility in soil(SRC). Volatilization of 1,3-cyclopentadiene from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.1X10-2 atm-cu m/mole(SRC), based upon its vapor pressure, 435 mm Hg(3), and water solubility, 1800 mg/L(4). 1,3-Cyclopentadiene is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(3). Biodegradation data in soil were not available(SRC, 2014).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 80(SRC), determined from a structure estimation method(2), indicates that 1,3-cyclopentadiene is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 2.1X10-2 atm-cu m/mole(SRC), derived from its vapor pressure, 435 mm Hg(4), and water solubility, 1800 mg/L(5). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 2.4 hours and 3.2 days, respectively(SRC). Olefins, as a general class, are susceptible to reaction with photochemically-produced hydroxyl radicals and singlet oxygen in natural waters(6). Half-lives are typically on the order of 13-14 days for olefins reacting with hydroxyl radicals and 40 days for cyclic olefins reacting with singlet oxygen(6). According to a classification scheme(7), an estimated BCF of 14(SRC), from an estimated log Kow of 2.25(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). 1,3-Cyclopentadiene is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). Biodegradation data in water were not available(SRC, 2014).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 1,3-cyclopentadiene, which has a vapor pressure of 435 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 1,3-cyclopentadiene 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 2.5 hours(SRC), calculated from its rate constant of 1.4X10-10 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Vapor-phase 1,3-cyclopentadiene is also degraded by reaction with ozone(SRC); the half-life for this reaction is estimated to be 52 minutes(SRC), calculated from its rate constant of 3.2X10-16 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Reaction of 1,3-cyclopentadiene with nitrate radicals in the night time atmosphere may also be a relevant removal mechanism(4).

The rate constant for the vapor-phase reaction of 1,3-cyclopentadiene with photochemically-produced hydroxyl radicals has been estimated as 1.4X10-10 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 2.5 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The rate constant for the vapor-phase reaction of 1,3-cyclopentadiene with ozone has been estimated as 3.2X10-16 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(1). This corresponds to an atmospheric half-life of about 52 min at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(1). Reaction of 1,3-cyclopentadiene with nitrate radicals in the night time atmosphere may also be a relevant removal mechanism(2). Reaction of 1,3-cyclopentadiene with atomic oxygen in air is expected to be too slow to be environmentally relevant (estimated half-life 5.9 days)(3). Highly concentrated solutions of 1,3-cyclopentadiene, such as those which may occur in spill situations or landfills(SRC), are expected to polymerize spontaneously and exothermally to dicyclopentadiene(4). 1,3-Cyclopentadiene is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). Olefins, as a general class, are susceptible to reaction with photochemically-produced hydroxyl radicals and singlet oxygen in natural waters(5). Half-lives are typically on the order of 13-14 days for olefins reacting with hydroxyl radicals and 40 days for cyclic olefins reacting with singlet oxygen(5).

An estimated BCF of 14 was calculated in fish for 1,3-cyclopentadiene(SRC), using an estimated log Kow of 2.25(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of 1,3-cyclopentadiene can be estimated to be 80(SRC). According to a classification scheme(2), this estimated Koc value suggests that 1,3-cyclopentadiene is expected to have high mobility in soil.

The Henry's Law constant for 1,3-cyclopentadiene is estimated as 2.1X10-2 atm-cu m/mole(SRC) derived from its vapor pressure, 435 mm Hg(1), and water solubility, 1800 mg/L(2). This Henry's Law constant indicates that 1,3-cyclopentadiene is expected to volatilize rapidly from water surfaces(3). 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)(3) is estimated as 2.4 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(3) is estimated as 3.2 days(SRC). 1,3-Cyclopentadiene's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). 1,3-Cyclopentadiene is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

DRINKING WATER: 1,3-Cyclopentadiene was qualitatively identified in drinking water at unspecified locations in the US(1-2). 1,3-Cyclopentadiene was detected at a concentration of 0.36 ppb in polluted drinking water from Czechoslovakia(3).

1,3-Cyclopentadiene was detected in the concentration range of 10-100 ug/L, in one out of 63 effluents from US industries(1). 1,3-Cyclopentadiene has been detected in stack emissions from waste incineration(2), and in emissions from polymer manufacture, polymer combustion, and biomass combustion(3). 1,3-Cyclopentadiene was reported in the atmosphere near an oil fire at 0.061 mg/cu m(4). Median concentrations in fireplace smoke of 1,3-cyclopentadiene were measured in mg/kg dry fuel used: 29.39 from soft wood, 35.05 from hard wood and synthetic wood 0.93; and measured from hard wood burned in wood stoves at 80.90(5). In the production of vertically aligned multi-walled carbon nanotubes, 1,3-cyclopentadiene emissions from the pre-heat step were 4.7 ppmV at 690 °C to 17.6 ppmV at 1040 °C(6).

1,3-Cyclopentadiene emissions from three types of fuel were found at 0.003% in average gasoline, 0.002% in EPA certified gasoline and at 0% in 85% methanol gasoline(1). Four-stroke lawn mower studies showed 0.21% of total emissions where 1,3-cyclopentadiene with regular gasoline and 0.16% with reformulated gasoline(2). Single cylinder engines found 1,3-cyclopentadiene emissions present only when using 1-hexene fuel and a 50/50 by volume mixture of n-hexane/toluene for fuel(3). 1,3-Cyclopentadiene had an annual minimum emission from automobiles of 0.412 ppm from 5,094 vehicles and maximum of 1.206 ppm from 6,600 vehicles(4).

1,3-Cyclopentadiene's production and use as a chemical intermediate may result in its release to the environment through various waste streams. If released to air, a vapor pressure of 435 mm Hg at 25 °C indicates 1,3-cyclopentadiene will exist solely as a vapor in the atmosphere. Vapor-phase 1,3-cyclopentadiene will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals and ozone; the half-lives for these reactions in air are estimated to be 2.5 hours and 52 min, respectively. Reaction of 1,3-cyclopentadiene with nitrate radicals in the night time atmosphere may also be a relevant removal mechanism. If released to soil, 1,3-cyclopentadiene is expected to have high mobility based upon an estimated Koc of 80. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 2.1X10-2 atm-cu m/mole. 1,3-Cyclopentadiene may volatilize from dry soil surfaces based upon its vapor pressure. If concentrated solution of 1,3-cyclopentadiene is released to soil or water (spilled), this compound is expected to polymerize spontaneously to dicyclopentadiene. If released into water, 1,3-cyclopentadiene 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 estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 2.4 hours and 3.2 days, respectively. An estimated BCF of 14 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 1,3-cyclopentadiene may occur through inhalation and dermal contact with this compound at workplaces where 1,3-cyclopentadiene is produced or used. Monitoring data indicate that the general population may be exposed to 1,3-cyclopentadiene via inhalation of ambient air, ingestion of contaminated drinking water, and dermal contact. (SRC)

1,3-Cyclopentadiene's production and use as a starting material for synthetic prostaglandins, for chlorinated insecticides, and the formation of sandwich compounds by chelation, for example, cyclopentadienyl iron dicarbonyl dimer(1), may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 80(SRC), determined from a structure estimation method(2), indicates that 1,3-cyclopentadiene is expected to have high mobility in soil(SRC). Volatilization of 1,3-cyclopentadiene from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.1X10-2 atm-cu m/mole(SRC), based upon its vapor pressure, 435 mm Hg(3), and water solubility, 1800 mg/L(4). 1,3-Cyclopentadiene is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(3). Biodegradation data in soil were not available(SRC, 2014).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 80(SRC), determined from a structure estimation method(2), indicates that 1,3-cyclopentadiene is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 2.1X10-2 atm-cu m/mole(SRC), derived from its vapor pressure, 435 mm Hg(4), and water solubility, 1800 mg/L(5). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 2.4 hours and 3.2 days, respectively(SRC). Olefins, as a general class, are susceptible to reaction with photochemically-produced hydroxyl radicals and singlet oxygen in natural waters(6). Half-lives are typically on the order of 13-14 days for olefins reacting with hydroxyl radicals and 40 days for cyclic olefins reacting with singlet oxygen(6). According to a classification scheme(7), an estimated BCF of 14(SRC), from an estimated log Kow of 2.25(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). 1,3-Cyclopentadiene is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). Biodegradation data in water were not available(SRC, 2014).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 1,3-cyclopentadiene, which has a vapor pressure of 435 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 1,3-cyclopentadiene 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 2.5 hours(SRC), calculated from its rate constant of 1.4X10-10 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Vapor-phase 1,3-cyclopentadiene is also degraded by reaction with ozone(SRC); the half-life for this reaction is estimated to be 52 minutes(SRC), calculated from its rate constant of 3.2X10-16 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Reaction of 1,3-cyclopentadiene with nitrate radicals in the night time atmosphere may also be a relevant removal mechanism(4).

The rate constant for the vapor-phase reaction of 1,3-cyclopentadiene with photochemically-produced hydroxyl radicals has been estimated as 1.4X10-10 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 2.5 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The rate constant for the vapor-phase reaction of 1,3-cyclopentadiene with ozone has been estimated as 3.2X10-16 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(1). This corresponds to an atmospheric half-life of about 52 min at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(1). Reaction of 1,3-cyclopentadiene with nitrate radicals in the night time atmosphere may also be a relevant removal mechanism(2). Reaction of 1,3-cyclopentadiene with atomic oxygen in air is expected to be too slow to be environmentally relevant (estimated half-life 5.9 days)(3). Highly concentrated solutions of 1,3-cyclopentadiene, such as those which may occur in spill situations or landfills(SRC), are expected to polymerize spontaneously and exothermally to dicyclopentadiene(4). 1,3-Cyclopentadiene is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). Olefins, as a general class, are susceptible to reaction with photochemically-produced hydroxyl radicals and singlet oxygen in natural waters(5). Half-lives are typically on the order of 13-14 days for olefins reacting with hydroxyl radicals and 40 days for cyclic olefins reacting with singlet oxygen(5).

An estimated BCF of 14 was calculated in fish for 1,3-cyclopentadiene(SRC), using an estimated log Kow of 2.25(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of 1,3-cyclopentadiene can be estimated to be 80(SRC). According to a classification scheme(2), this estimated Koc value suggests that 1,3-cyclopentadiene is expected to have high mobility in soil.

The Henry's Law constant for 1,3-cyclopentadiene is estimated as 2.1X10-2 atm-cu m/mole(SRC) derived from its vapor pressure, 435 mm Hg(1), and water solubility, 1800 mg/L(2). This Henry's Law constant indicates that 1,3-cyclopentadiene is expected to volatilize rapidly from water surfaces(3). 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)(3) is estimated as 2.4 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(3) is estimated as 3.2 days(SRC). 1,3-Cyclopentadiene's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). 1,3-Cyclopentadiene is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

DRINKING WATER: 1,3-Cyclopentadiene was qualitatively identified in drinking water at unspecified locations in the US(1-2). 1,3-Cyclopentadiene was detected at a concentration of 0.36 ppb in polluted drinking water from Czechoslovakia(3).

1,3-Cyclopentadiene was detected in the concentration range of 10-100 ug/L, in one out of 63 effluents from US industries(1). 1,3-Cyclopentadiene has been detected in stack emissions from waste incineration(2), and in emissions from polymer manufacture, polymer combustion, and biomass combustion(3). 1,3-Cyclopentadiene was reported in the atmosphere near an oil fire at 0.061 mg/cu m(4). Median concentrations in fireplace smoke of 1,3-cyclopentadiene were measured in mg/kg dry fuel used: 29.39 from soft wood, 35.05 from hard wood and synthetic wood 0.93; and measured from hard wood burned in wood stoves at 80.90(5). In the production of vertically aligned multi-walled carbon nanotubes, 1,3-cyclopentadiene emissions from the pre-heat step were 4.7 ppmV at 690 °C to 17.6 ppmV at 1040 °C(6).

1,3-Cyclopentadiene emissions from three types of fuel were found at 0.003% in average gasoline, 0.002% in EPA certified gasoline and at 0% in 85% methanol gasoline(1). Four-stroke lawn mower studies showed 0.21% of total emissions where 1,3-cyclopentadiene with regular gasoline and 0.16% with reformulated gasoline(2). Single cylinder engines found 1,3-cyclopentadiene emissions present only when using 1-hexene fuel and a 50/50 by volume mixture of n-hexane/toluene for fuel(3). 1,3-Cyclopentadiene had an annual minimum emission from automobiles of 0.412 ppm from 5,094 vehicles and maximum of 1.206 ppm from 6,600 vehicles(4).

1,3-Cyclopentadiene was detected in the gas phase of tobacco smoke at levels ranging from 0.06-7 ug/cigarette, with the amount of cyclopentadiene increasing with increasing tar delivery(1).

According to the 2006 TSCA Inventory Update Reporting data, the number of persons reasonably likely to be exposed in the industrial manufacturing, processing, and use of 1,3-cyclopentadiene is 1-99; the data may be greatly underestimated(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 51 workers (none of these were female) were potentially exposed to 1,3-cyclopentadiene in the US(1). Occupational exposure to 1,3-cyclopentadiene may occur through inhalation and dermal contact with this compound at workplaces where 1,3-cyclopentadiene is produced or used. Monitoring data indicate that the general population may be exposed to 1,3-cyclopentadiene via inhalation of ambient air, ingestion of contaminated drinking water, and dermal contact(SRC).

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. 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 soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

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.

Incineration

Flammable liquids, n.o.s. require a label "FLAMMABLE LIQUIDS". Quantity limitations: Passenger aircraft/rail: 60L; Cargo aircraft only: 220L. It falls in Hazard Class 3 and Packin Group III.

Flammable Liquid

Airtight. Unbreakable packaging.

UN Hazard Class: 3; UN Pack Group: III