Workplace exposure limits (WEL) in Australia: a complete guide

What are workplace exposure limits in Australia?

A workplace exposure limit (WEL) is the highest airborne concentration of a substance that a worker can breathe in. Australia sets one for hundreds of dusts, fumes, vapors, mists and gases, and businesses must keep exposure at or below each limit.

How workplace exposure limits work

Safe Work Australia publishes the WEL list, and the model WHS Regulations make it mandatory. Under regulation 49, a business must make sure no one at the workplace breathes a substance above its limit. Each state and territory applies the list through its own WHS laws, so your regulator has the final say. The list changes on December 1, 2026, alongside the old name, workplace exposure standards, also changes to align with international practice.

The numbers come from health evidence. Safe Work Australia reviewed trusted international sources to set limits that protect most workers from both short and long term effects.

Just because there is a limit doesn’t mean it’s safe for everyone. Some people, including those with heart or lung conditions, can react below it. That’s why employers still need to reduce exposure as far as reasonably practicable.

How the time limits work

A short-term limit isn't a free pass for four bad quarter-hours. Exposure at the 15-minute limit can't last longer than 15 minutes, can't happen more than four times a day and needs at least 60 minutes between spells. Peak limits are stricter still, because nobody may breathe above one at any time.

Long shifts can also lower the eight-hour limit. If people work more than eight hours a day, 40 hours a week or get less than 16 hours between shifts, the employer may need to adjust the limit down, and a qualified professional can work out by how much.

How to find the limit for a chemical

Start with your register of hazardous substances, then look up each substance.

• Get the safety data sheet. It names the substance and its CAS number, which is the safest way to match it on the list. A safety data sheet checklist helps you confirm each one is current.

• Search the list. The WEL list shows each chemical with its synonyms and CAS number.

• Cross-check the database. Safe Work Australia's chemical database lists the current limits for each chemical.

• Read the units. Dusts and fumes use mg/m³, and gases and vapors use ppm. When an entry shows both, the ppm figure is the exact one.

• Check the particle size. Dust limits apply to the inhalable fraction unless the entry says respirable.

• Read the notations. Codes like Sk (skin), DSEN, RSEN and OTO flag extra risks, and notes e and f flag extra rules such as health monitoring or restrictions.

A missing limit doesn't remove your duty. Under the model WHS Act, employers must still eliminate health risks so far as is reasonably practicable, and a hazardous substances checklist helps you cover the rest.

Your legal duties under the WHS laws

The duty sits with the business, known as a person conducting a business or undertaking (PCBU). It covers everyone at the workplace, visitors included.

Three provisions matter most, and the WEL list sets them out:

• Regulation 49 bars exposure above a limit.

• Regulation 50 requires air monitoring when you aren't certain whether you're under a limit, or when you need monitoring to find out if there's a risk to health.

• Section 19 of the WHS Act is the primary duty to protect workers and others at the workplace so far as is reasonably practicable.

Who enforces the limits

State and territory regulators enforce the laws. Safe Work Australia writes the model laws but doesn't regulate them, and Victoria runs its own OHS laws. Maximum penalties differ by jurisdiction, so check what applies where you operate.

Air monitoring: how to show you comply

Air monitoring tells you what workers actually breathe. Safe Work Australia says a competent and experienced person, such as an occupational hygienist, should do it and interpret the results, and it should happen after controls are in place.

Monitoring means measuring the contaminant in the worker's breathing zone with a personal sampler. The sampler stays on through normal work and routine breaks, and a sampler left at a fixed spot in the room can't show compliance on its own.

Keep monitoring records for at least 30 years, and make sure workers can access them.

Health monitoring is a separate duty

Air monitoring checks the air. Health monitoring checks the worker. A registered medical practitioner monitors workers who face a significant risk from certain hazardous chemicals, such as those listed in Schedule 14 of the model WHS Regulations. Notes on the WEL list show which chemicals may trigger it.

Where the limits matter most

Limits apply wherever dust, fumes or vapors get into the air. Here's what that looks like in four industries:

• Construction: respirable silica from cutting concrete, which has a limit of 0.05 mg/m³, plus cement dust and softwood dust.

• Mining: diesel exhaust, which gets a respirable limit of 0.01 mg/m³, along with silica and coal dust.

• Manufacturing: welding fumes, which have a limit of 1 mg/m³, plus solvents like toluene and acetone.

• Food production: flour dust, which gets a limit of 0.5 mg/m³, plus grain dust and cleaning chemicals like peracetic acid.

Your chemical register matters more than your industry. The limits that apply to you depend on what you use and what your work produces.