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 1/8)
Character Range: 2780192–2783221

3                   Tetrachloroethene (PCE)

3.1              General
Several comprehensive reviews of tetrachloroethene in the environment and its toxicity to humans are available and should be consulted for more detailed information not presented in this summary (ATSDR 1997; WHO 2006; NICNAS 2001; US EPA 2012). The following provides a summary of the key aspects of PCE that is relevant to the derivation of interim HILs.

Tetrachloroethene, also known as perchloroethylene (PCE) and tetrachloroethylene, is a synthetic, colourless, volatile, non-flammable liquid, with a characteristic sharp, sweet odour. It has a relatively low solubility in water and is commonly used as a dry-cleaning and metal degreasing solvent (ATSDR 1997). PCE manufacture in Australia ceased in 1991. Use in Australia has declined from 1995, consistent with declining use worldwide. PCE is primarily imported in its 'pure' form with approximately 80 % used in the dry cleaning industry in Australia (NICNAS 2001)

PCE is widespread in the environment and is found in trace amounts in water, aquatic organisms, air, foodstuffs, and human tissue. The highest environmental levels of PCE are found in the commercial dry-cleaning and metal degreasing industries. PCE may degrade in the environment to more toxic compounds, including vinyl chloride (WHO 2006).

3.2              Previous HIL
No previous HIL is available for PCE (NEPC 1999).

3.3              Proposed Interim HIL
Review of available information in relation to the presence of PCE in soil indicates that the vapour inhalation pathway is the most significant/important. This pathway should be assessed based on measured vapour data, in particular, soil vapour data. There are significant limitations in the derivation of a soil HIL, in particular, the modelling of phase partitioning from soil to soil vapour and the field measurement of volatiles in soil; hence, an interim HIL has been derived for soil vapour only.

The following presents the values adopted for the calculation of a soil vapour interim HIL. In addition other information that is relevant to the assessment of PCE in soil (relevant to other pathways of exposure) is presented.

3.4              Significance of Exposure Pathways

    3.4.1         Inhalation
PCE is a volatile compound and, as such, the derivation of the HIL has considered the vapour inhalation pathway. The approach adopted for the quantification of potential vapour migration to outdoor air and intrusion indoors is outlined in Schedule B7. It is noted that the derived HIL is dominated by the assessment of these pathways of exposure. Due to limitations with the vapour modelling approach adopted, the HILs derived are considered interim.

The inhalation of particulates outdoors and indoors is considered essentially insignificant, compared with vapour inhalation.

    3.4.2         Dermal absorption
Insufficient data is available on the dermal absorption of PCE from soil. Given the volatility of the compound, dermal absorption is expected to