Some people hear the words “health and safety”, roll their eyes and mutter about “fun police”.
In my 22 years in occupational health and safety, that was never my intent. But from call centre workers to fuel truck drivers, each role does hold inherent risks, and those risks need to managed. That is what occupational health and safety is – minimising the risk of harm for workers.
Something else from the past is driveway service at the servo (that’s Australian for service station, or gas station).
At one point in my career, I had to do a risk assessment for benzene exposure for a service station that still did driveway service.
Names have been changed or blanked to protect the innocent (or, not so innocent).
Health Surveillance – Exposure to benzene from driveway service
Executive Summary
This report looks at the need for health surveillance associated with exposure to benzene in fuel vapours while providing driveway service at unnamed service station. Driveway service was, in 2011, considered a unique selling point to drive sales at this outlet.
Based on mean and exposure levels quoted in the 1997 National Environmental Health Monograph on benzene, and average sales through this outlet, health surveillance was not required for unnamed service station.
Health hazards associated with benzene
Benzene, a constituent of unleaded petrol, is a Category 1 carcinogen, and by law is restricted to less than 1% by volume per litre of unleaded petrol. The primary route of exposure for the generalpopulation, including staff at retail fuel outlets, is via inhalation of vapours while refuelling cars, in exhaust and in cigarette smoke. This risk assessment looks exclusively at exposure from vapours while carrying out driveway service at unnamed service station.
Health effects
(From MSDS provided by supplier Mobil Exxon.)
ACUTE: Inhalation of this product’s vapours can cause headaches, nausea, dizziness, and drowsiness.
Severe inhalation overexposures may be fatal, due to asphyxiation.
CHRONIC: Chronic exposure to Benzene causes serious damage to the health by all routes of exposure. Chronic oral and inhalation exposure causes severe effects on the blood system (e.g. damage to the bone marrow). Effects can occur with an exposure level as low as 10 ppm for 24
weeks. Benzene also causes harmful changes to the immune system, decreasing the production of mature B- and T- white blood cells. Benzene is a confirmed human carcinogen, which can produce Hodgkin’s Disease, leukaemia and lymphomas by inhalation. Benzene is a potential reproductive toxin.
Existing data
There is no data currently available for atmospheric monitoring at unnamed service station.
Data has been obtained from the National Environmental Health Monograph for benzene, which quotes a 1993 study where benzene concentrations in air were measured in 83 samples from 11 service stations in major cities across Australia. 8-hour average samples were collected next to pumps. The mean concentration for these samples was 107 ppb (range 20 – 600 ppb). The monograph concluded that individuals will therefore be exposed briefly to relatively high concentrations of benzene.
Evaluating the potential exposure of employees
Australian fuel standards require that motor spirit contains no more benzene than 1% by volume.
Unnamed service station sells an average of 22,000 litres of unleaded petrol each week, and is a low volume site, with an average of 6 sales per hour and an average of 31 litres per sale.
The monograph for benzene produced by the National Environmental Health Forum in 1997 quotes a study carried out in 1993, where benzene concentration in air were measured in 83 samples from 11 service stations in major cities across Australia, with 8-hour average samples collected adjacent to pumps. This showed the mean concentration for these samples to be 107 ppb (range 20-600 ppb). Ppb means parts per billion.
The exposure limit, TWA is 1ppm. Converting the maximum measurement in the range of 600ppb to
0.6ppm, an employee conducting driveway service will receive less than the allowable exposure limit
during their occupational exposure.
Atmospheric monitoring
It is not industry practice to conduct atmospheric monitoring for the presence of benzene and other chemicals in the air around pumps and bowsers unless it is required by local authorities to support Development Applications of the retail site itself or neighbouring developments.
Environmental health initiatives to reduce public exposure to VOCs (volatile organic compounds) have seen the introduction of Stage 1 Vapour Recovery to manage vapours during the bulk loading process. Stage 1 Vapour Recovery is in place at this site. Stage 2 Vapour Recovery, to capture vapours during car refuelling, had not yet been implemented in 2011, but is in new service stations in 2024. The introduction of Stage 2 vapour recovery is estimated to reduce vapours in the atmosphere by approximately 95%.
Health surveillance
Health surveillance is mandated for petroleum industry workers, where atmospheric contamination is an ever-present hazard. Health surveillance is not mandated for retail fuel outlet workers.
Health Watch, the pre-eminent health surveillance study for the petroleum industry in Australia, specifically excludes retail service station workers as exposure at retail worksites is generally similar to that of the general community, i.e. the occupational exposure is very low. Employees who smoke are exposed to benzene in cigarette smoke at far greater rates than is possible through vapours from fuelling a vehicle.
Recommendation
Health surveillance is not required for our employees who provide driveway service at unnamed service station.
Sources
- MSDS – Unleaded Petrol, Mobil Oil Australia Pty Ltd
- Health Watch – The Australian Institute of Petroleum Health Surveillance Program, Monash
University, Melbourne, 2007 - Benzene, National Environmental Health Monographs, Department of Human Services, Adelaide, 1997
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