Hidden Risks of Benzene Spikes: Why Periodic Monitoring Isn’t Enough
Dangers of Benzene Exposure in Australian Industries
Benzene is a hydrocarbon that is toxic and carcinogenic to humans. Acute exposure to benzene can cause narcosis, headaches, dizziness, drowsiness, confusion, tremors, and loss of consciousness. In the long term, chronic exposure to benzene is strongly associated with a range of cancers including leukemia and lung cancer. Preventing and mitigating benzene exposure is critical due to these deadly health consequences.
Benzene exposure is a significant hazard in a wide range of industries in Australia including:
Oil and Gas – Benzene occurs naturally in crude oil and is released during extraction, refining and handling. This poses a risk to workers involved in all aspects from drilling to maintenance of petroleum infrastructure.
Chemical and Petrochemical Manufacturing – Benzene is used in the manufacturing of products such as rubber, lubricants, detergents, and pesticides. It is also used to make chemicals used in the production of plastics, resins, and nylon.
Steel Manufacturing – Benzene containing compounds are produced as a byproduct of the coking process. These benzene byproducts are often collected due to its value in producing other products.
Contaminated Land Remediation – Benzene is often present alongside other volatile organic compounds (VOC). VOC’s pose a hazard where land is contaminated by underground petrol storage tanks or spillage that results in soil and groundwater contamination.
There is a particularly high risk of benzene exposure in confined spaces. Since benzene is heavier than air it can accumulate in poorly ventilated or low-lying areas. It is therefore essential for workers entering confined spaces such as sewers or basements to be aware of the increased risk of benzene exposure.
Continuous vs Periodic Monitoring for Benzene
Under the Workplace Exposure Standards for Airborne Contaminants(WES), workers must not be exposed to more than an eight-hour time weighted average (TWA) of 3.2 mg/m3 or 1 ppm of benzene. This is one of the lowest limits for VOC, demonstrating the high risk of adverse health consequences when exposed to excessive levels of benzene.
Note that the WES is to be changed to the Workplace Exposure Limits (WEL) as of the 1st of December 2026.
Portable Benzene Monitoring
Portable gas detectors (other than portable area gas monitors) are used periodically to monitor the concentration of a gas that a person is exposed to. Portable photoionisation detectors (PID) such as the Cub TAC (total aromatic compounds) monitor the concentration of benzene in the atmosphere. They are commonly worn by a worker in their breathing zone or are handheld like the Tiger XT Select Benzene PID.
Portable gas detectors are ideal for spot checks, personal protection, and short-term tasks. They travel with workers, alerting them in real-time if they enter a hazardous atmosphere and are essential for confined space entry, maintenance work, and mobile operations. Generally, portable PID gas like the Cub TAC detectors measure the overall amount of VOC or TAC but do not measure benzene specifically. Some handheld PID detectors such as the Tiger XT Select, are capable of specifically measuring benzene but require a benzene pre-filter tube.
These portable gas detectors are used to assess the risk of exposure associated with a specific task or area that is suspected of being contaminated with benzene. For example, the Cub TAC may alert a worker to high TAC in confined space. Appropriate respiratory protective equipment (RPE) can then be worn, and the space can be assessed in further detail using the Tiger XT Select to more accurately determine whether the benzene concentration exceeds exposure limits.
The risk is that benzene levels can spike intermittently during heating, blending, or transferring fuels and chemicals - then drop back down before the next portable reading is taken. If only checking periodically such as when using a portable gas detector, the peaks can be missed.
Fixed System Benzene Monitoring
The Ion Science TITAN 2 is the only fixed gas detector that specifically monitors benzene. It runs 24/7, continuously monitoring the concentration of a gas such as benzene in a specific area. This makes it useful in areas where a degree of benzene exposure is expected or there is a risk of breaking containment that requires constant monitoring. Every 60 seconds it draws an air sample, filters out interference from other VOCs, and delivers a precise benzene reading down to 0.02 ppm - well below Australia’s exposure limit.
This around-the-clock monitoring ensures that all benzene spikes are recorded. This is essential in places such as offshore oil rigs or mine sites where people not only work in the area but also live. They can also be used to conduct boundary monitoring and detect vapour intrusion to monitor benzene exposure beyond the immediate worksite or where there is soil contamination. Fixed gas detectors are also generally compatible with industrial interfaces such as MODBUS which allow for integration with ventilation systems so that when benzene reaches certain concentrations, ventilation and other control measures activate to immediately mitigate risk to personnel.
What Type of Benzene Monitoring is Best?
Ultimately, monitoring decisions must be appropriate for the specific application and there is no one-size-fits all approach. Portable gas detectors are essential as they provide data representative of the exposure of an individual, but they do not offer the same continuous monitoring required to comprehensively identify benzene spikes that fixed gas detectors do. Portable gas monitoring and fixed gas detection serve different purposes and are often both needed to gain a full understanding of worker exposure and overall benzene concentration in an area.
Key Takeaways
Benzene is a toxic and carcinogenic substance found in industries such as oil & gas, chemical manufacturing, steel production, and contaminated land remediation, with confined spaces posing heightened risks.
Australia’s exposure limit for benzene is among the strictest, reflecting the serious health consequences of both acute and chronic exposure.
Portable gas detectors are vital for task-specific and personal protection, but they may miss short-lived benzene spikes due to their periodic nature.
Fixed gas detectors provide continuous, precise monitoring, making them essential for high-risk or residential work environments such as offshore rigs and mine sites.
A combined monitoring strategy is often necessary, using portable detectors for individual exposure and fixed systems for area-wide, continuous surveillance.
