Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:10:p1
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 10 (pt 1/4)
Character Range: 2569992–2572964

10             Toxaphene

10.1          General
Several comprehensive reviews of toxaphene in the environment and its toxicity to humans are available and should be consulted for more detailed information (ATSDR 1996; IARC 2001). The following provides a summary of the key aspects of toxaphene that are relevant to the derivation of a soil HIL.

Toxaphene is a mixture of over 670 compounds produced via the chlorination of camphenes from pine resins. Toxaphene is the active ingredient in a class of insecticides produced under a number of trade names including the following: Alltox, Attac, Camphechlor, chlorinated camphene, Compound 3956, Huilex, Melipax, Motox, Strobane-T, Texadust and Toxakil (ATSDR 1996). In its original form, toxaphene is a yellow, waxy solid with a chlorine or turpentine-like odour. It is highly insoluble in water but readily soluble in aromatic hydrocarbons. It is not flammable and evaporates slowly when in its solid form or when mixed with liquids (ATSDR 1996; IARC 2001).

Toxaphene was manufactured and used as a non-systemic, contact insecticide from the late 1940s. Its use was banned in Australia (since 1987) and much of the world in the 1980s; however, toxaphene is still used (to some degree) in some developing regions of the world including Africa, Asia and South America (ATSDR 1996). Insecticide products containing toxaphene were primarily used on cotton, cereal grains, fruits, nuts and vegetables and were also used to control lice, ticks and mites in livestock and fish populations in water bodies (ATSDR 1996; IARC 2001). Toxaphene was never used in Australia, with any registered products cancelled in 1987.

10.2          Previous HIL
No previous HIL is available for toxaphene (NEPC 1999).

10.3          Significance of Exposure Pathways

10.3.1     Oral Bioavailability
Insufficient data is available to adequately define the bioavailability of toxaphene hence a default approach of assuming 100% oral bioavailability has been adopted in the derivation of an HIL. It is noted that a site-specific assessment of bioavailability can be undertaken where required.

10.3.2     Dermal absorption
Insufficient data is available on the dermal absorption of toxaphene from soil. Hence the default value of 0.1 (10%) suggested by US EPA (1995) for pesticides has been adopted in the derivation of HILs.

10.3.3     Inhalation of Dust
Toxaphene is not considered sufficiently volatile to be of significance and inhalation exposures associated with particulates outdoors and indoors are expected to be of less significance than ingestion of soil. While likely to be negligible, potential inhalation exposures associated with dust have been considered in the HIL derived.

10.3.4     Plant Uptake
Limited data is available on the potential for plant uptake of toxaphene. ATSDR (1996) notes that toxaphene is not expected to be available to humans via ingestion of plants unless they have been recently treated with the mixture.