p.2Environmental hazards and risks

p.2Environmental hazards and risks

All States and Territories have general environment protection legislation pertaining to pollution and contaminated land. However, there are currently no existing leak prevention or leak detection requirements for operators of underground fuel storage tanks in NSW, and probably other States and Territories, to detect and control leakages from UST facilities. UST leak detection systems are implemented on a voluntary basis by industry, particularly by major petroleum suppliers.

Use of MMT in internal combustion engines as a fuel additive and subsequent degradation through combustion, and its short persistence in the environment, indicate that aquatic and terrestrial organisms are unlikely to be exposed to MMT at or above levels of concern through existing use as an AVSR. A low environmental risk is predicted.

Manganese, the principle degradation by-product from combustion of MMT, is naturally occurring and ubiquitous in the environment. It is an essential nutrient of plants and animals. Environmental exposure to Mn compounds will mostly arise through the gaseous phase. Eventually, these will deposit to land and waters. The emission of Mn into the environment from use of fuels containing MMT is unlikely to develop to levels of concern and therefore poses a low risk for terrestrial or aquatic environments.

The findings of this assessment highlight the potential for leaking USTs to pose an unacceptable risk to the environment. Such leakages represent localised, point source discharge, but have the potential to detrimentally affect significant areas of the environment. Although a large number of USTs have been replaced or have had leak detection systems or other measures installed, most USTs do not have leak detection systems, and many that are currently in service are old and have the potential to leak in the future if not decommissioned or replaced.

Although there is potential for risk to the environment from leakage of fuel (which may or may not contain MMT) from USTs, the risk would be site specific.

There is currently no environmental hazard classification system in Australia. In accordance with the OECD Globally Harmonized System of Classification and Labelling of Chemicals, MMT would be classified Chronic 1 Very Toxic to Aquatic Life with Long-lasting Effects (OECD, 2002).

p.3Occupational health and safety risks

Although MMT is toxic by oral, dermal and inhalation routes, the enclosed processes used predominantly for blending of fuel or fuel additives where concentrates are handled renders the possibility of exposure low. Mild irritation is possible upon contact with fuels or fuel additives containing MMT but given the significant dilution of MMT with petroleum distillates, irritation is likely due to the irritant properties of the petroleum distillates more than the MMT itself.

Exposure to MMT is possible during handling of additised fuels, fuel additives and automotive fuel system components but is expected to be infrequent, minor and of short duration and limited due to its dilution with solvents and other additives in the fuel and fuel additives. Overall, the risks to workers posed by MMT during formulation and during handling of fuels, fuel additives containing MMT and automotive fuel system components contaminated with MMT is low.

The main route of exposure to Mn particulates is inhalation and in occupations where automotive usage is ubiquitous, chronic inhalation of inorganic Mn species may result. A worst-case scenario was considered for Mn exposure of Australian auto mechanics from the use of MMT. Using overseas personal inhalational exposure estimates, a Margin of Exposure of 203 for local mechanics was derived. This is considered a sufficient Margin of Exposure given the conservative exposure estimates derived from data from Canada where MMT is used widely as an octane enhancer in fuels and ambient air levels of Mn are higher and calculations assuming 100% market share for MMT. Therefore, the occupational health risks associated with Mn exposure from MMT combustion are assessed as low.

MSDS and labels for imported MMT concentrates and formulated aftermarket additives were assessed qualitatively against the NOHSC MSDS and Labelling Codes. In general, labels were lacking ingredient information and although some relevant hazard warnings were present, the recommended risk and safety phrases from this assessment were missing. Signal words and disclosure of the presence of MMT were also missing from some labels. Local contact details were absent from labels of imported concentrates. MSDS in general contained relevant health effect information but also did not include recommended risk and safety phrases. Most also had other important elements missing such as correct hazard statements and emergency telephone numbers. A sample MSDS for MMT is included in Appendix 3.

MMT (as Mn) is listed in the NOHSC Exposure Standards for Atmospheric Contaminants in the Occupational Environment with an exposure standard of 0.2 mg/m³, (8 h TWA), skin notation (NOHSC 1995b).