How are hazardous substances identified in the workplace?

Hazardous substances are usually identified by looking at what materials you use, store, or produce during work. Most companies start with a simple inventory: checking chemical labels, safety data sheets (SDS), and any by-products created from your processes — like fumes, dusts or vapours. Sometimes hazards aren’t obvious, for example wood dust or welding fumes, so a walk-through inspection helps spot risks people might overlook.

A competent person (often a hygienist, safety manager or external consultant) will then review each substance to understand what harm it could cause — irritation, illness, cancer risks, etc. COSHH requires that employers don’t just look at the chemical itself but how it’s used: spraying, grinding, heating, or cutting all increase exposure potential.

In many cases, monitoring is recommended to confirm what workers are actually breathing in during a normal shift.