Hexachlorocyclopentadiene

Hazardous Air Pollutants (HAPs)

Toxic Gases & Vapors -> Other Toxic Gases & Vapors

Corrosives

Pesticide -> EPA IRIS

Volatile Organic Compound (VOC) and(or) Semi-Volatile Organic Compound (SVOC) (Pesticide)

log Kow= 5.04

4/5

5.04

1.7019 at 77 °F (EPA, 1998) - Denser than water; will sink

1.7019 at 25 °C/4 °C

Relative density (water = 1): 1.7

1.71

1.7019 @25 °C

1.71

Dense, oily liquid

Pale-yellow to amber-colored liquid.

less than 0.1 mg/mL at 70.7 °F (NTP, 1992)

Soluble in all proportions in acetone, carbon tetrachloride, methanol and hexane.

In water, 1.8 mg/L at 25 °C

Solubility in water, g/100ml at 25 °C: 0.2

(77 °F): 0.0002% (Reacts)

462 °F at 753 mmHg (EPA, 1998)

239 °C

239 °C

462 °F

239 °C @760 [mm Hg]

462 °F

Danger

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

P260, P262, P264, P270, P271, P273, P280, P284, P301+P317, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P320, P321, P330, P361+P364, P363, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

Danger

H302 (96.2%): Harmful if swallowed [Warning Acute toxicity, oral]

P260, P261, P262, P264, P264+P265, P270, P271, P272, P273, P280, P284, P301+P317, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P320, P321, P330, P333+P317, P361+P364, P362+P364, P363, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

Chemical: 1,3-Cyclopentadiene, 1,2,3,4,5,5-hexachloro-

Hazard Traits - Hematotoxicity; Hepatotoxicity and Digestive System Toxicity; Nephrotoxicity and Other Toxicity to the Urinary System; Respiratory Toxicity

1,3-Cyclopentadiene, 1,2,3,4,5,5-hexachloro- is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of 1,3-Cyclopentadiene, 1,2,3,4,5,5-hexachloro- are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

Status: Active Update: 09-05-2018 https://echa.europa.eu/registration-dossier/-/registered-dossier/20469

Hexachlorocyclopentadiene: Does not have an individual approval but may be used as a component in a product covered by a group standard. It is not approved for use as a chemical in its own right.

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

Toxic hydrogen chloride, chlorine, and phosgene gases may form in fires. In presence of moisture, will corrode iron and other materials; flammable and explosive hydrogen gas may collect in enclosed space. Will corrode iron and other metals in the presence of moisture. Reacts slowly with water to form hydrochloric acid; however, the reaction is not hazardous. Hazardous polymerization may not occur. (EPA, 1998)

· Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.

Not combustible. Gives off irritating or toxic fumes (or gases) in a fire.

This compound is very toxic and may be fatal if inhaled, swallowed, or absorbed through the skin. The probable human lethal dose is 50-500 mg/kg, or between 1 teaspoon and 1 ounce for a 150 lb. (70 kg) person. Severe exposure induces pulmonary hyperemia and edema, degenerative and necrotic changes in brain, heart and adrenal glands and necrosis of liver and kidney tubules. (EPA, 1998)

· Highly toxic, may be fatal if inhaled, ingested or absorbed through skin.

HCCPD is a manufactured chemical that does not occur naturally. It is a light, lemon-yellow liquid that has a sharp musty odor. It easily evaporates into the air; the vapor looks like a blue haze. HCCPD is used in the manufacture of certain pesticides. Most of the HCCPD in the environment results from releases during its production and disposal. It is also used to make flame retardants, resins that won't burn, shock-proof plastics, esters, ketones, fluorocarbons, and dyes.

Hexachlorocyclopentadiene is an intermediate in the manufacture of some pesticides. Hexachlorocyclopentadiene is very toxic following acute (short-term) oral and inhalation exposures. The chemical is a severe eye, skin, and pulmonary irritant in humans, with effects including tearing of the eyes, sneezing, salivation, blistering, burns, and cough from acute exposures. Limited information is available on chronic (long-term), reproductive, developmental, and cancer effects of hexachlorocyclopentadiene in humans. Animal studies have seen effects on the lung, liver, kidney, and blood. EPA has classified hexachlorocyclopentadiene as a Group D, not classifiable as to human carcinogenicity.

Corrosive to skin; [Quick CPC] Contact with liquid may cause blistering of the skin. [CHRIS] Daily exposures to 0.34 ppm cause pulmonary edema as well as liver and kidney injury in experimental animals. Workers avoid exposure because of its odor and irritating properties. [ACGIH]

2646 151

2646 151

Atallah YH et al; Toxicol Halogenated Hydrocarbons: Health Ecol Eff (Pap Symp): 344-55 (1981). A review on the environmental fate of hexachlorocyclopentadiene.

USEPA; Health Effects Assessment for Hexachlorocyclopentadiene (1986) EPA 540/1-86/001.

WHO; Environ Health Criteria 120: Hexachlorocyclopentadiene (1991). Available from: http://www.inchem.org/documents/ehc/ehc/ehc120.htm as of July 1, 2004.

DHHS/NTP; Toxicology & Carcinogenesis Studies of Hexachlorocyclopentadiene in F344/N Rats and B6C3F1 Mice (Inhalation Studies) Technical Report Series No. 437 (1994) NIH Publication No. 94-3168

Isolate hazard area and deny entry. Wear positive pressure breathing apparatus and special protective clothing. Fight fire from maximum distance. Dike fire control water for later disposal.

In case of fire in the surroundings, use appropriate extinguishing media.

Fresh air, rest. Half-upright position. Artificial respiration may be needed. Refer for medical attention.

Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer for medical attention .

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

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

· 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.

· Do not touch damaged containers or spilled material unless wearing appropriate protective clothing.

Warning: Effects may be delayed. Caution is advised. Vital signs should be monitored closely.

General First Aid:

(General first aid procedures)

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

TIH (Toxic Inhalation Hazard) - Term used to describe gases and volatile liquids that are toxic when inhaled. Some are TIH materials themselves, e.g., chlorine, and some release TIH gases when spilled in water, e.g., chlorosilanes. [ERG 2016].

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./ Cover solids with a plastic sheet to prevent dissolving in rain or fire fighting water. Absorb bulk liquid with fly ash or cement powder.

Environmental considerations. Water spill: Use natural deep water pockets, excavated lagoons or sand bag barriers to trap material at bottom. Remove trapped material with suction hoses. Use mechanical dredges or lifts to remove immobilized masses of pollutants and precipitates.

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

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U130, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

A potential 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. A potential 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 potential 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.

The following wastewater treatment technology have been investigated for hexachlorocyclopentadiene: Concentration process: Stripping.

Recommendable Treatment and Disposable Methods: Incineration. Incineration after mixing with another combustible fuel. Care must be exercised to assure complete combustion to prevent the formation of phosgene. An acid scrubber is necessary to remove the halo acids produced.

HCCPD is a potential candidate for fluidized bed incineration at a temperature range of 450-980 °C and residence times of seconds for liquids and gases, and longer for solids. It is also a potential candidate for rotary kiln incineration at a temperature range of 820-l ,600 °C and residence times of seconds for liquids and gases, and hours for solids. HCCPD is also a candidate for liquid injection incineration at a temperature range of 650-1,600 °C and a residence time of 0.1-2 seconds. Rotary kiln or fluidized bed incineration methods are acceptable disposal methods for these wastes. HCCPD can be incinerated after mixing with a combustible fuel; however, this mixture should be completely combusted to prevent the formation of phosgene, and an acid scrubber is necessary to remove the halogen acids produced.

Personal protection: chemical protection suit including self-contained breathing apparatus. Do NOT let this chemical enter the environment. Collect leaking and spilled liquid in sealable plastic containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.

... Limited uses ... are not expected to result in significant levels of residues in humans ... except in factory & other workers who may be directly exposed at work.

Urine samples obtained during May and June 1978 from workers at the Memphis (TN) North Treatment Plant contained hexachlorocyclopentadiene(1).

After oral exposure of HCCPD, gastric lavage is recommended. Following inhalation, move patient to fresh air. Monitor for respiratory distress. If cough or difficulty breathing develops, evaluate for respiratory tract irritation, bronchitis, or pneumonitis. Administer oxygen and assist ventilation as required. Treat bronchospasm with inhaled beta2 agonist and oral or parenteral corticosteroids. Irrigate exposed eyes with copious amounts of room temperature water for at least 15 minutes. If the exposure occurs through dermal contact with the toxin, remove contaminated clothing and wash exposed area thoroughly with soap and water. Treat dermal irritation or burns with standard topical therapy. Patients developing dermal hypersensitivity reactions may require treatment with systemic or topical corticosteroids or antihistamines. (T36)

Hepatic (Liver), Renal (Urinary System or Kidneys), Respiratory (From the Nose to the Lungs)

Gastrointestinal

Eyes, skin, respiratory system, liver, kidneys

Patients exposed to HCCPD may get a sore throat or have shortness of breath and chest discomfort. Bleeding, swelling, and fluid buildup can occur in the lungs. The linings of the respiratory passages and the lungs are very susceptible to damage from low concentrations of HCCPD following inhalation exposure. Inflammation of the tissues can be followed by necrosis, exfoliation, and hemorrhage. Tissue repair is often fibrous in appearance. Long-term exposure to very low levels of HCCPD can produce granular yellow-brown pigmentation of the epithelium of the nose, trachea, larynx, and lungs. High acute oral doses of HCCPD are associated with liver necrosis and tissue degeneration. The kidneys also appear to be a target tissue for HCCPD toxicity. Degenerative lesions in the tubules can result from small oral doses. (L437)

LC50 Pimephales promelas (Fathead minnow, early juvenile) 6.7 ug/L/30 days; flow-through

LC50 Pimephales promelas (Fathead minnow, larval) 7.0 ug/L/96 hr; flow-through

LC50 Penaeus duorarum (Pink shrimp) 0.34 ug/L/96 hr /Conditions of bioassay not specified in source examined/

LC50 Microhyla ornata (Ornate narrow-mouthed frog) 7.3 mg/L/96 hr /Conditions of bioassay not specified in source examined/

For more Ecotoxicity Values (Complete) data for HEXACHLOROCYCLOPENTADIENE (21 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), the average Koc value of 4,265 from 15 different soils(2) indicates that hexachlorocyclopentadiene is expected to have low mobility in soil(SRC). Volatilization of hexachlorocyclopentadiene from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 0.027 atm-cu m/mole(3). Hexachlorocyclopentadiene is not expected to volatilize from dry soil surfaces(SRC) based on a vapor pressure of 0.060 mm Hg(4). Volatilization losses of 0.84-1.60% from moist sand, 0.35-0.67% from moist loam, and 0.15-0.285% from moist humus were observed over a two hour period in a laboratory study, carried out at 25 °C, where the initial hexachlorocyclopentadiene concentration was 50 ug/kg soil on a dry weight basis(5). Radiolabeled hexachlorocyclopentadiene at an initial concentration of 1 mg/kg was added to soil contained in a glass flask covered with perforated aluminum foil and kept on a laboratory shelf which was exposed to sunlight. After 7 days incubation, recovery of nonpolar compounds (hexachlorocyclopentadiene and nonpolar metabolites) was 6.1% in unaltered, nonsterile soil (approx 72% was polar and nonextractable), approx 6% in nonsterile soil at pH 4, approx 9% in nonsterile soil at pH 8, 36.1% in autoclaved soil (33.5% was polar and nonextractable), approx 15% in sodium azide treated soil, and approx 3% in flooded (anaerobic) soil. These data indicate that loss of hexachlorocyclopentadiene from soil is the result of abiotic and biotic degradation(6).

AQUATIC FATE: Based on a classification scheme(1), the average Koc value of 4,265 from 15 different soils(2) indicates that hexachlorocyclopentadiene is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon a Henry's Law constant of 0.027 atm-cu m/mole(4); however adsorption may attenuate volatilization(3). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 2 hours and 7 days, respectively if adsorption is ignored(SRC). The volatilization half-life from a model pond is estimated as 37 days if adsorption is considered(5). According to a classification scheme(6), BCF values in the range of 100-1354 measured in fish(7-10), suggest bioconcentration in aquatic organisms is very high(SRC).If released to water, hexachlorocyclopentadiene will degrade primarily by photolysis and chemical hydrolysis. During daylight hours, hexachlorocyclopentadiene found in clear, shallow water is expected to photodegrade with a half-life on the order of several minutes(4). 2,3,4,4,5-Pentachloro-2-cyclopentenone, hexachloro-2-cyclopentenone, and hexachloro-3-cyclopentenone have been identified as primary photodegradation products of hexachlorocyclopentadiene. In unlit or deep, turbid water, chemical hydrolysis is expected to be an important fate process. Hydrolytic half-lives ranging from several hours to 2-3 weeks are predicted for waters with temperatures in the range of 20-30 °C(4,11). An aqueous screening test showed that hexachlorocyclopentadiene was totally degraded in 7 days using domestic wastewater as inoculum(12). Both hydrolysis and biodegradation were potential degradation pathways.

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), hexachlorocyclopentadiene, which has a vapor pressure of 0.06 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase hexachlorocyclopentadiene 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 29 days(SRC), calculated from its rate constant of 3.9X10-13 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Hexachlorocyclopentadiene absorbs light greater than 290 nm(4) and has been shown to undergo direct photolysis rapidly(5). Hexachlorocyclopentadiene adsorbed onto silica gel, underwent 46.0% photomineralization when irradiated with UV light (>290 nm) for 17 hours(5).

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

inhalation, skin absorption, ingestion, skin and/or eye contact

Inhalation (L442) ; oral (L442) ; dermal (L442) ; eye contact (L442)

HCCPD may interact with the microsomes that binds to secretory molecules and changes their ability to be transported from the cell. It can be postulated, that some of its toxic properties are a consequence of its reactivity in Diels-Alder reactions where a conjugated diene combines with a substituted or unsubstituted alkene (a dienophile) in a cycloaddition reaction. Biological tissues contain a large number of potential reactants for cycloaddition reactions. HCCPD can also undergo addition and substitution reactions or be oxidized by way of the mixed function oxidase system. Effects of HCCPD on the brain may also be a reflection of the reaction of either HCCPD or a metabolite with brain lipids. The effects of HCCPD on the adrenal glands may be a reflection of its ability to combine with the unsaturated carbons in sterols produced by this gland. The hydroxyl functional group of a sterol is on a carbon adjacent to the double bond and can activate that bond to cycloaddition reactions. Such reactions would require exposure to large doses of HCCPD so that reactive material would reach the adrenal gland. HCCPD is excreted in urine and feces. (L437)

/AQUATIC SPECIES/ Acclimated normal rainbow trout were exposed to 130 ppb hexachlorocyclopentadiene in a flow through well water circuit which was designed to permit measurements of oxygen consumption by the fish. Compared to pre-hexachlorocyclopentadiene values, hexachlorocyclopentadiene increased oxygen consumption rates by 186 + or - 24%, with maximum oxygen consumption rates being reached in 84 min after hexachlorocyclopentadiene exposure. Oxygen consumption subsequently decreased, and all hexachlorocyclopentadiene exposed fish died within 6.5 hr of exposure. Fish exposed to hexachlorocyclopentadiene free vehicle (acetone) showed no changes of oxygen consumption. When added to normal isolated trout heart mitochondria, hexachlorocyclopentadiene appeared to uncouple oxidative phosphorylation, with calculated respiratory control ratios being decreased 50% from control values at a hexachlorocyclopentadiene concentration of 0.41 umole.

/AQUATIC SPECIES/ ...30-day early-life stage flow-through toxicity tests /were conducted/ with fathead minnows (Pimephales promelas) using measured concentrations and 1-day-old larvae. The 96-hr LC50 value was 7 ug/L. The 96-hr mortality data indicated a sharp toxicity threshold, such that 94% survival was observed at 3.7 ug/L, 70% at 7.3 ug/L, and 2% at 9.1 ug/L. At the end of the 30-day exposure period, mortality was only slightly higher, with 90% survival at 3.7 ug/L, 66% at 7.3 ug/L, and 0% at 9.1 ug/L. These results indicated that the median lethal threshold, the lowest concentration causing 50% mortality, was reached within 4 days. In addition, the HEX residues found in fathead minnows at the end of the 30-day tests were low (<0.1 ug/g), and a BCF value of <11 was reported. The authors concluded that the toxicity data and the BCF values indicated that HEX was non-cumulative in fish, i.e. it did not bioconcentrate in fish as a result of continuous low-level exposure to HEX. The growth rate of surviving larvae, measured in terms of both body length and weight, did not decrease significantly at any of the concentrations tested, compared with the controls. This was true even at 7.3 ug/L, a level greater than the calculated LC50 value. Based on these toxicity and growth data, /it was/ concluded that 3.7 ug/L is the highest concentration of HEX that produces no adverse effects on fathead minnow larvae.

Cough. Sore throat. Headache. Diarrhoea. Dizziness. Nausea. Vomiting. Laboured breathing.

MAY BE ABSORBED! Redness. Pain. Skin burns.

Redness. Pain. Blurred vision. Severe deep burns.

Abdominal pain. Burning sensation. Shock or collapse. Further see Inhalation.

irritation eyes, skin, respiratory system; eye, skin burns; lacrimation (discharge of tears); sneezing, cough, dyspnea (breathing difficulty), salivation, pulmonary edema; nausea, vomiting, diarrhea; In Animals: liver, kidney injury

Inhalation of HCCPD can cause cough, sore throat, headache, diarrhoea, dizziness, nausea, vomiting, and laboured breathing. Ingestion of HCCPD can cause abdominal pain,burning sensation, shock or collapse. Dermal exposure can cause redness, pain and skin burns. Eye exposure can cause redness, pain, blurred vision, and severe deep burns. (L442)

U130; As stipulated in 40 CFR 261.33, when hexachlorocyclopentadiene, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to Federal and/or State hazardous waste regulations. Also defined as a hazardous waste is any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5).

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. Hexachlorocyclopentadiene is included on this list.

Listed as a hazardous air pollutant (HAP) generally known or suspected to cause serious health problems. The Clean Air Act, as amended in 1990, directs EPA to set standards requiring major sources to sharply reduce routine emissions of toxic pollutants. EPA is required to establish and phase in specific performance based standards for all air emission sources that emit one or more of the listed pollutants. Hexachlorocyclopentadiene is included on this list.

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 10 lb or 4.54 kg. The toll free number of the NRC is (800) 424-8802; In the Washington D.C. metropolitan area (202) 426-2675. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).

Releases of CERCLA hazardous substances are subject to the release reporting requirement of CERCLA section 103, codified at 40 CFR part 302, in addition to the requirements of 40 CFR part 355. Hexachlorocyclopentadiene is an extremely hazardous substance (EHS) subject to reporting requirements when stored in amounts in excess of its threshold planning quantity (TPQ) of 100 lbs.

Toxic pollutant designated pursuant to section 307(a)(1) of the Federal Water Pollution Control Act and is subject to effluent limitations.

Hexachlorocyclopentadiene is designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance. This designation includes any isomers and hydrates, as well as any solutions and mixtures containing this substance.

... Based on available toxicity data, to protect public health the derived /criterion/ level is 206 ug/l ... .

It can be postulated, ...that some of its toxic properties are a consequence of its reactivity in Diels-Alder reactions where a conjugated diene combines with a substituted or unsubstituted alkene (a dienophile) in a cycloaddition reaction. Biological tissues contain a large number of potential reactants for cycloaddition reactions (quinones, sterols, 2-alkenoic acids, unsaturated fatty acids, and unsaturated fatty acid derivatives). HCCPD can also undergo addition and substitution reactions or be oxidized by way of the mixed function oxidase system. The attack of HCCPD on tissues can be regarded as a 2-phase phenomenon. Primary lesions are formed by direct contact of the material with exposed tissues (nasal passages, lungs, forestomach, and skin). These lesions can be hypothesized to result from reactions of HCCPD or one of its metabolites with epithelial cells impairing function and resulting in cell death. Once exposure ceases, new cells replace the damaged ones, and slow recovery begins. Secondary lesions form at sites distant from the point of contact when systemic circulation carries unreacted HCCPD or a metabolite to lungs, liver, kidney, heart, brain, and adrenals. These tissues may become targets for HCCPD by virtue of their physiological function (liver and kidney) or the tendency for their cell products or membrane components to react with HCCPD or an HCCPD metabolite (lung, adrenal).

The effects of HCCPD on the adrenal glands may be a reflection of its ability to combine with the unsaturated carbons in sterols produced by this gland. The hydroxyl functional group of a sterol is on a carbon adjacent to the double bond and can activate that bond to cycloaddition reactions. Such reactions would require exposure to large doses of HCCPD so that reactive material would reach the adrenal gland.

Its half-life was approx 9 days in goldfish.

...Rats were exposed to 14C-/hexachlorocyclopentadiene/ (HEX) vapor... for a period of 1 hr and received doses in air which ranged from 1.4 to 37.4 mg/kg bw. ...Elimination during the subsequent 6 hr appeared to relate to a complex pharmacokinetic model with a terminal rate comparable to that reported for the intravenous route, the half-life being approximately 30 hr.

Hexachlorocyclopentadiene underwent chemical alterations in water forming both lipophilic and hydrophilic products. The lipophilic nonpolar products in fish were extremely volatile. Three days after the ip injection of (14)C hexachlorocyclopentadiene, the ethyl acetate extractable radioactivity was approx 47% while water solubles and unextractables were 11 and 20% of the injected radioactivity, respectively. Ethyl acetate extracts of fish included at least 8 unidentified breakdown products. Water solubles from fish included at least 4 unidentified products.

...The ability of liver, fecal, and gut homogenates to metabolize HEX in vitro /was studied/. In an apparent first-order kinetic process, HEX was metabolized by gut content, fecal, and liver homogenates with half-lives of 10.6, 1.6, and 14.2 hr, respectively. When mercuric chloride (HgCl2) was added to the gut and fecal homogenates as a bacteriocide, the half-lives were increased to 17.2 and 6.2 hr, respectively, indicating that the gut and fecal flora contributed significantly to the metabolism of HEX. Denaturation of the liver homogenate had virtually no effect on the in vitro metabolic rate indicating, perhaps, that there was only limited involvement of liver microsomes or other enzyme-dependent process.

No primary metabolites or conjugates of HEX have been identified. ...The principal routes of excretion were shown to be via the urine and feces. No unchanged HEX was found in either, indicating that HEX was involved in extensive metabolism.

HCCPD is rapidly metabolized and distributed to blood, liver, kidneys, and lungs before being distributed to the peripheral tissues. (L437)

Rats given 6 mg/kg hexachlorocyclopentadiene (HEX) orally excreted 33% in urine, 10% in feces in 7 days. Most excretion occurred during 1st 24 hr after dosing. Kidney retained 0.5%, liver >0.5%. Biliary excretion of only 16% with 66% still voided in the feces of bile duct cannulated rats suggested that the majority of orally consumed HEX was not absorbed. Degradation apparently occurred in the gut since little of the fecal material was of an apolar nature. The kidney, liver, ovaries and fat were the major sites of deposition of (14)C-HEX equivalents. In rats, the kidney contained the highest levels of residues, whereas in mice the residues in the liver exceeded those in the kidney. Other than this difference, the fate of HEX in rats and mice, both male and female, was quite similar and in each case the tissue residues reached a plateau after about two weeks on the HEX-containing diets.

Studies were conducted to determine the fate and retention time of (14)C-hexachlorocyclopentadiene in rats. The test animals were either exposed to (14)C-hexachlorocyclopentadiene vapors for single 1 hr periods, or dosed orally with (14)C-hexachlorocyclopentadiene in corn oil. Tissue, urine, and feces samples were analyzed, as well as expired air, to assess the fate and retention time. Approximately 84% of the inhaled compound is retained. Inhaled (14)C-hexachlorocyclopentadiene excreted in the urine; orally administered (14)C-hexachlorocyclopentadiene eliminated in the feces. In rats exposed by inhalation, the trachea and lung had the highest residue accumulation. In animals receiving oral doses kidneys and liver were major sites of accumulation. These studies indicate that the route of exposure is critical to the pattern of retention and elimination.

The differential disposition of hexachlorocyclopentadiene (C56) following oral administration, as contrasted to inhalation or iv administration, may account for its lower toxicity by this route. After iv dose of (14)C labeled C56 to rats at 0.59 mg/kg, 39% of the radioactivity remained in the tissues at 72 hr; after inhalation of vapors of (14)C C56 (1.3-1.8 mg/kg), this amount was 11.5%. After oral doses of 4.1 or 61 mg/kg, the amount was only 2.4%.

(14)C-Hexachlorocyclopentadiene (HEX, C56) was administered as a single oral dose (2.5 and 25 mg/kg) as a component of the diet (1, 5 and 25 ppm) for a maximum of 30 days. Route of excretion was via the feces (-70% of dose) with low elimination in the urine (approximately 15%). Biliary excretion of only 16% still voided in the feces of bile duct cannulated rats suggested that the majority of orally consumed HEX was not absorbed. Degradation apparently occurred in the gut since little of the fecal material was of an apolar nature. The kidney, liver, ovaries and fat were the major sites of deposition of (14)C-HEX equivalents. In rats, the kidney contained the highest levels of residues, whereas in mice the residues in the liver exceeded those in the kidney. Other than this difference, the fate of HEX in rats and mice, both male and female, was quite similar and in each case the tissue residues reached a plateau after about two weeks on the HEX-containing diets.

For more Absorption, Distribution and Excretion (Complete) data for HEXACHLOROCYCLOPENTADIENE (6 total), please visit the HSDB record page.

Hexachlorocyclopentadiene is the key intermediate in the manufacture of some pesticides, including heptachlor, chlordane, aldrin, dieldrin, and endrin. Hexachlorocyclopentadiene is also used in the manufacture of flame retardants and some resins and dyes.

Used in the manufacture of some chlorinated pesticides; [ACGIH]

For hexachlorocyclopentadiene (USEPA/OPP Pesticide Code: 027502) there are 0 labels match. /SRP: Not registered for current use in the U.S., but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./

/Used to make/ ...shock proof plastics, acids, esters, ketones, and fluorocarbons.

The principal end use for /hexachlorocyclopentadiene/ (HCCPD) is as a key intermediate in the production of chlorinated cyclodiene pesticides, including aldrin, dieldrin, endrin, chlordane, heptachlor, kepone, endosulfan, pentac, isodrin, and mirex. Technical grade chlordane, for example, has been reported to contain impurities of HCCPD up to 1%; /it was/ also reported that HCCPD was present as a contaminant in several cyclodiene pesticides at concentrations of up to 1%.

It is also used as an intermediate in the manufacture of flame retardants such as Dechlorane Plus and chlorendic anhydride and, to a lesser extent, in the manufacture of nonflammable resins, polyester resins, pharmaceuticals, unbreakable plastics, acids, esters, ketones, fluorocarbons, and dyes. It has previously been used as a biocide.

Technical grade Hex usually contains other chemicals as contaminants of manufacture (eg, hexachlorobenzene and octachlorocyclopentene). The nature and levels of contaminants will vary with the method of production.

Impurity concentrations in one 97.4% pure sample of HCCPD included 0.15% tetrachloroethylene, 0.51% hexachloro-1,3-butadiene, 1.73% octachlorocyclopentene, and 0.48% hexachloro-3-cyclopentene-1-one. A 98% pure sample contained 0.4% hexachlorobutadiene and 1.5% hexachloro-3-cyclopentene-l-one. Other impurities that have been reported in HCCPD include hexachlorobenzene, PCBs, and mirex.

2023: 141,094 lb

(1977) PROBABLY GREATER THAN 4.54X10+6 G

(1982) PROBABLY GREATER THAN 2.27X10+6 G

CHLORINATION OF CYCLOPENTADIENE, FOLLOWED BY CATALYTIC CHLORINATION OVER PHOSPHORUS PENTACHLORIDE OR ARSENIC OXIDE, THEN THERMAL DECHLORINATION.

Liquid phase chlorination of pentane to form polychloropentanes. Then, vapor phase chlorination and ring closure using a porous surface active inorganic catalyst. ... A similar process was patented in the USSR in 1957 using tetrachloropentene as the feed.

HCCPD may be produced commercially by chlorination of cyclopentadiene or dechlorination of octachlorocyclopentene. In the chlorination process, cyclopentadiene is mixed with alkaline hypochlorite and HCCPD is recovered by fractional distillation. The maximum yield of product is about 75 percent, with impurities including lower chlorinated cyclopentadienes. The dechlorination process involves thermal dechlorination of octachlorocyclopentene at 470-480 °C and yields a product of greater than 90 percent purity.

GRADES: Technical

Trade Names: C 56, NCI-C55607, HRS 1655, and Graphlox.

1,3-Cyclopentadiene, 1,2,3,4,5,5-hexachloro-: ACTIVE

... Technical chlordane has contained ... hexachlorocyclopentadiene ... /as impurity/.