The Occupational Safety and Health Act and chemicals at work

The Occupational Safety and Health Act Cap. 231 is the main law protecting workers from occupational hazards, including hazardous chemicals. It is administered by the Ministry of Gender, Labour and Social Development through the Department of Occupational Safety and Health. It was amended by the Occupational Safety and Health (Amendment) Act, No. 20 of 2025, which came into force on 25 July 2025.

Employers' chemical-related duties

• Identify the hazardous substances workers handle and control their exposure.
• Keep a chemical register and a Safety Data Sheet for each substance.
• Make sure hazardous chemicals are labelled. Highly toxic substances need pre-authorisation.
• Provide adequate ventilation, suitable PPE, and washing and eyewash facilities.
• Arrange regular medical surveillance for workers exposed to hazardous chemicals.
• Train workers, plan for emergencies, and report occupational accidents and diseases.

Workers' duties. Workers must follow safe procedures, use the PPE provided and report dangerous situations. Training should make clear that these are legal obligations, not optional good practice.

How it fits with environmental law. One drum of solvent is covered by both regimes:

• the National Environment Act Cap. 181 and the Hazardous Chemicals Regulations, 2024 govern its registration, licensing, storage, transport, spills and disposal;
• the OSH Act governs how workers are protected while handling it.

A compliant site needs both: a NEMA licence and register, and a workplace exposure assessment with PPE, training and health surveillance.

The 2025 amendment. The amending Act took effect in July 2025. Employers should read it alongside the principal Act and check their OSH policies, registers and reporting procedures against it. Do not rely on summaries of the 2006 text.

What to do

• Check that your chemical register and SDS file cover every substance in use, including those held by contractors.
• Confirm medical surveillance is in place for workers exposed to carcinogens, sensitisers or corrosives.
• Map PPE to SDS Section 8 for each task.
• Review your OSH procedures against the 2025 amendment.

How INRC can help

INRC’s occupational health and safety work covers chemical registers, exposure assessments, PPE selection and emergency planning. We measure workplace gases and dust with our own calibrated instruments through our environmental monitoring service. Contact us to discuss your site.

This article is general guidance, not legal advice. Check current legislation and regulations for your specific project.