Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:3:p1
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 3 (pt 1/6)
Character Range: 2418861–2421959

3                   Pentachlorophenol (PCP)

3.1              General
Several comprehensive reviews of pentachlorophenol (PCP) in the environment and its toxicity to humans are available and should be consulted for more detailed information not presented in this summary (ATSDR 2001; WHO 1987). The following provides a summary of the key aspects of PCP that are relevant to the derivation of a soil HIL.

Pure pentachlorophenol is a colourless, white or light tan crystalline solid (WHO 1987; ATSDR 2001). It has a characteristic phenolic odour at high temperatures but it is relatively odourless at room temperature. Pentachlorophenol is moderately volatile at ambient temperature and insoluble in water (WHO 1987; ATSDR 2001). Technical grade pentachlorophenol is typically 86% pure and is dark grey to brown in colour as a result of the polychlorinated phenol impurities. It is typically manufactured in the form of dust, beads or flakes (ATSDR 2001).

Pentachlorophenol is an effective biocide and had wide applications in the commercial and agricultural industries as an insecticide (termiticide), fungicide, herbicide, molluscicide and algicide. The primary use of the compound was for wood preservation. In the United States, the use of wood products treated with pentachlorophenol in domestic settings was banned but the compound is still used to preserve power line poles, railroad sleepers, wharf pilings, cross arms and fence posts (ATSDR 2001). Pentachlorophenol was also historically used as a disinfectant, as an ingredient in antifouling paint, as an insecticide or herbicide in domestic environments, in the textile industry, leather industry, in mineral oil and in glue (WHO 1987; ATSDR 2001).

Pentachlorophenol is no longer registered as the active ingredient in any chemical in Australia.

Review of the toxicity of PCP is complicated by the relatively large database on the toxicity of technical-grade PCP and the comparatively small database on pure PCP. Technical-grade PCP has been shown to contain a large number of impurities, including tetrachlorophenols and, to a much lesser extent, polychloro-dibenzodioxins, polychlorodibenzofurans, polychlorodiphenyl ethers, polychloro-phenoxy phenols and chlorinated hydrocarbons. These impurities, in particular the polychloro-dibenzodioxins and furans, are indicated to be responsible for at least some of the observed toxicity of the technical-grade PCP (MfE 2011). Notwithstanding, specific haematopoietic cancer risks are observed with PCP exposure and which are not likely to be due to dioxins or other chlorophenol contaminants (Cooper & Jones 2008).

3.2              Previous HIL
No previous HIL has been derived for PCP (NEPC 1999).

3.3              Significance of Exposure Pathways

    3.3.1         Oral Bioavailability
Insufficient data is available to adequately define the bioavailability of PCP in the range of contaminated sites that may need to be considered in Australia. On this basis, a default approach of assuming 100% oral bioavailability has been adopted in the derivation of an HIL. It is noted that a