Toxaphene

2019-10-27

Toxaphene (also known as chlorinated camphene) is a mixture of approximately 200 organic compounds, formed by the chlorination of camphene (C10H16) to an overall chlorine content of 67-69 % by weight. The bulk of the compounds (mostly chlorobornanes, chlorocamphenes, and other bicyclic chloroorganic compounds) found in Toxaphene have chemical formulas ranging from C10H11Cl5 to C10H6Cl12, with a mean formula of C10H10Cl8. The formula weights of these compounds range from 308 to 551 grams/mole; the theoretical mean formula has a value of 414 grams/mole. Toxaphene is usually seen as a yellow to amber waxy solid, but may occur as a gas. It has a piney odour and is volatile enough to be transported for long distances through the atmosphere. [1,2]

Uses [4]

Toxaphene was used as a nonsystemic stomach and contact insecticide from the late 1940s until 1982 (peaking in 1975), when the EPA cancelled all uses of it as a pesticide or pesticide ingredient. It was used mainly on cotton, but also on flowers because it was persistent and relatively nontoxic to bees. Toxaphene was used to control insects on cotton, corn, fruit, vegetables, and small grains as well as to protect livestock from such pests as lice, fleas, ticks, mange, and scab mites. Up through the early 1970s, Toxaphene, often mixed with rotenone, was used widely in lakes and rivers to eradicate fish that were considered a detriment to sport fishing. This occurred most often in Canada and the Northern United States. Its use as a pesticide was cancelled in 1982, all uses were banned in 1990, and existing stocks were not to be sold in the United States after 1 March 1990. It is currently used only for the following:

  • Scabies control in cattle (as a dip)
  • Insect control for pineapples in Puerto Rico and for bananas in the Virgin Islands
  • Emergency treatment of cotton, corn, and small grains
  • “Toxaphene-like pesticides” are still produced and used in other countries including in India, parts of Eastern Europe, Latin America, and Africa.

In the Environment [2]

When released to the environment, Toxaphene can enter the air, the soil, and water. It does not dissolve well in water and evaporates easily. Toxaphene is more likely found in air, soil, and sediment at the bottom of lakes or streams, than in surface water. It can stay in the environment for a long time because it breaks down very slowly. Toxaphene can be carried long distances in the air and accumulates in fatty tissues of fish and mammals.

Sources & Routes of Exposure

Sources of Exposure [2]

People may be exposed to Toxaphene if they live near a location with heavy contamination, such as a hazardous waste site. The exposure may occur at higher levels through breathing contaminated air or through direct skin contact with contaminated soil or water. In addition, people who consume large quantities of fish, shellfish, or wild game animals from areas contaminated with Toxaphene may have higher exposure to this substance since these animals tend to accumulate Toxaphene in fatty tissues. Individuals may be exposed to Toxaphene through drinking water contaminated with Toxaphene runoff from contaminated soils.

Routes of Exposure [3]

  • Inhalation – There is some potential for inhalation exposure among populations living near waste sites that contain Toxaphene and its degradation products.
  • Oral – Potential routes of exposure are via consumption of food sources (e.g.,fish and aquatic mammals) that contain Toxaphene residues, or via Toxaphene-contaminated drinking water.

Health Effects [5]

Acute Effects

Acute oral exposure to Toxaphene in humans results in central nervous system (CNS) stimulation, with the major effect being convulsive seizures. The dose necessary to induce nonfatal convulsions in humans is approximately 10 milligrams per kilogram body weight per day (mg/kg/day). No studies are available on the effects of acute inhalation exposure to Toxaphene in humans or animals. Animal studies have reported effects on the liver, kidney, and CNS from acute oral exposure to Toxaphene.

Chronic Effects

Chronic inhalation exposure to Toxaphene in humans has been reported to cause reversible respiratory toxicity. In animals, chronic oral exposure to Toxaphene has resulted in effects on the liver (induction of microsomal enzymes and histological changes in liver cells), kidney, spleen, adrenal and thyroid glands, CNS, and immune system (immunosuppressive effects). EPA has not established a Reference Concentration (RfC) or a Reference Dose (RfD) for Toxaphene. ATSDR has calculated an oral intermediate minimal risk level (MRL) of 0.001 mg/kg/d based on no adverse liver effects in rats.

Reproductive/Developmental Effects

No information is available on the developmental or reproductive effects of Toxaphene in humans following inhalation or oral exposure. Animal studies have reported developmental effects, including behavioural effects and immunosuppression, in the offspring of rats exposed orally to Toxaphene. Several studies have reported no reproductive effects from oral exposure to Toxaphene in animals.

Cancer Risk

Several human studies examined the incidence of cancer associated with inhalation exposure to Toxaphene. However, these studies were inconclusive due to lack of information on exposure levels and concurrent exposure to other pesticides. A study by the National Toxicology Program (NTP) reported an increase in liver tumours in male and female mice and an increase in thyroid tumours in male and female rats when fed Toxaphene in the diet. EPA considers Toxaphene to be a probable human carcinogen (cancer-causing agent) and has classified it as a Group B2 carcinogen.

Safety [6]

First Aid Measures

  • Inhalation: Remove to fresh air.
  • Skin Contact: Flush with water.
  • Eye Contact: Immediately flush with water for a minimum of 15 minutes.
  • Ingestion: Methanol may be fatal or cause blindness. Seek immediate medical attention.
  • Note to Physician: Effects may be delayed. Ethanol may inhibit methanol metabolism.
  • After following first aid measures, seek medical attention.

Fire Fighting Measures

  • Flammable properties: flammable liquid. Vapour may travel considerable distance to source of ignition and flash back.
  • Extinguishing media: Dry chemical, carbon dioxide or appropriate foam.
  • Unique aspects contributing to a fire: Methanol burns with a clear, almost invisible flame.
  • Note: As in any fire, wear self-contained breathing apparatus, and full protective gear.

Storage & Handling

  • Keep container tightly closed.
  • Avoid contact with skin and eyes.
  • Store at 2-6°C.
  • Avoid sources of ignition.
  • Handle in accordance with good laboratory practices. This product is intended for use only by people trained in the safety and handling of chemicals and laboratory preparations.

Exposure Controls/Personal Protection

  • Handle in accordance with good laboratory practices.
  • Respiratory Protection: Not normally needed. If exposure limits are exceeded, use approved/certified respirator.
  • Eye Protection: Splash goggles.
  • Skin Protection: Neoprene or other chemical resistant gloves. Disposable nitriles are acceptable for light intermittent exposure.
  • Engineering Controls: Work in a fume hood or use general or other local exhaust ventilation to meet Exposure Limits.

Regulation [7]

United States

OSHA: The Occupational Safety & Health Administration has set the following Permissible Exposure Limit (PEL) for Toxaphene:

  • General Industry: 29 CFR 1910.1000 Z-1 Table — 0.5 mg/m3 TWA; Skin
  • Construction Industry: 29 CFR 1926.55 Appendix A — 0.5 mg/m3 TWA; Skin
  • Maritime: 29 CFR 1915.1000 Table Z-Shipyards — 0.5 mg/m3 TWA; Skin

ACGIH: The American Conference of Governmental Industrial Hygienists has set a Threshold Limit Value (TLV) for Toxaphene of 0.5 mg/m3 TWA; 1 mg/m3 STEL; Skin; Appendix A3 – Confirmed Animal Carcinogen with Unknown Relevance to Humans

NIOSH: The National Institute for Occupational Safety and Health has identified Toxaphene as a Potential Occupational Carcinogen

Australia

Safe Work Australia: Safe Work Australia has set an average 8-hour time weighted concentration for toxaphene of 0.5 mg/m3 and a 15-minute short term exposure limit of 1 mg/m3.

Refereces

http://en.wikipedia.org/wiki/Toxaphene

http://www.atsdr.cdc.gov/toxfaqs/tfacts94.pdf

http://www.atsdr.cdc.gov/toxguides/toxguide-94.pdf

http://toxipedia.org/display/toxipedia/Toxaphene

http://www.epa.gov/ttn/atw/hlthef/toxaphen.html

http://www.eraqc.com/DesktopModules/ERAMSDS/ViewPDF.aspx?id=1edf6e54-b4fa-47f8-9073-b9c3ed1fc244

https://www.osha.gov/dts/chemicalsampling/data/CH_226300.html