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Workplace Safety Guide

Chemical Safety: Managing Hazardous Substances at Work

A practical guide to identifying chemical hazards, assessing the risks, implementing controls, and keeping the records that protect your people and your organisation.

Applicable to all workplaces globally — Updated February 2026

Why Chemical Safety Matters

Hazardous substances are found in almost every workplace — from cleaning products in offices to solvents in manufacturing, pesticides in agriculture, and fumes in welding shops. The Health and Safety Executive estimates that over 13,000 deaths a year in Great Britain are linked to occupational lung disease and cancers caused by past work exposures to chemicals.

The legal framework varies by country — COSHH in the UK, OSHA HazCom in the USA, WHS in Australia, and similar regulations in most jurisdictions — but the underlying approach is the same: identify the hazard, assess the risk, put controls in place, and monitor their effectiveness.

Getting this right protects workers from acute and chronic harm, reduces your liability exposure, and demonstrates the due diligence that regulators and insurers expect.

Types of Chemical Hazard

Understanding the category of hazard is the starting point for risk assessment.

Toxic

Substances that can cause serious harm or death at relatively small doses (e.g., carbon monoxide, hydrogen cyanide).

Corrosive

Substances that destroy living tissue on contact, including strong acids and alkalis (e.g., sulphuric acid, sodium hydroxide).

Flammable / Explosive

Substances that can ignite or explode (e.g., solvents, aerosols, flammable gases, reactive metals).

Irritant / Sensitiser

Substances that cause skin, eye, or respiratory irritation or that can trigger long-term allergic reactions (e.g., isocyanates, epoxy resins).

Carcinogenic / Mutagenic

Substances that cause or contribute to cancer or genetic damage (e.g., benzene, silica dust, asbestos).

Environmental Hazard

Substances harmful to aquatic life or ecosystems, subject to strict storage and disposal requirements.

Many substances present multiple hazards. Isocyanates, for example, are both toxic and sensitisers. Your assessment must address all hazard categories associated with each substance.

Safety Data Sheets (SDS)

A Safety Data Sheet (SDS) — previously called a Material Safety Data Sheet (MSDS) — is the primary technical document for a hazardous substance. Suppliers of hazardous substances are legally required to provide one. The format is standardised globally under the GHS (Globally Harmonised System), meaning every SDS has the same 16 sections regardless of where it was produced.

The 16 Sections of a Safety Data Sheet

1.Identification of the substance and supplier
2.Hazard identification (GHS classification)
3.Composition and ingredient information
4.First aid measures
5.Fire-fighting measures
6.Accidental release measures
7.Handling and storage requirements
8.Exposure controls and personal protection
9.Physical and chemical properties
10.Stability and reactivity
11.Toxicological information
12.Ecological information
13.Disposal considerations
14.Transport information
15.Regulatory information
16.Other information (including SDS revision date)

Always use the current SDS

Formulations change. An SDS that is 5 years old may not reflect the current hazard classification or exposure limits. Request updated SDS from suppliers periodically — at minimum every 3 years — and whenever there is a change to the substance or regulations.

SDS vs. Label — they're different

The GHS label on a container gives immediate hazard information at a glance. The SDS provides the detailed technical information needed to assess the risk and choose appropriate controls. Both are required — the label for day-to-day identification, the SDS for risk assessment and emergency response.

Hazardous Substance Risk Assessment

A hazardous substance assessment documents the risks from using a substance in a specific task and the controls in place to reduce those risks. It must be suitable and sufficient — a phrase used by regulators to mean it genuinely reflects the actual risk, not a generic or template document that hasn't been adapted to your workplace.

What a Good Assessment Covers

1. Identify the substance

Name, SDS reference, location used, quantities typically present.

2. Identify who could be harmed

Direct users, workers in adjacent areas, cleaners, maintenance staff, visitors, contractors.

3. Identify the routes of exposure

Inhalation (vapours, dust, mist, fumes), skin/eye contact, ingestion, injection.

4. Assess the level of risk

Consider frequency and duration of exposure, concentration, task characteristics, and existing controls.

5. Determine the controls needed

Apply the control hierarchy — see below. Compare with Workplace Exposure Limits (WELs) or Occupational Exposure Limits (OELs) where applicable.

6. Record and review

Document the assessment. Review when the substance, task, or controls change — or at least annually.

Single substances vs. mixtures: Assessments can cover a single hazardous substance or a group of similar substances used in the same way (e.g., all water-based cleaning products used by the cleaning team). Where substances are used together or in sequence, consider combined or cumulative exposure effects.

The Control Hierarchy

Controls should be applied in order of effectiveness. PPE alone is rarely sufficient — it's a last resort, not a substitute for engineering or process controls.

1

Elimination

Most effective

Remove the hazardous substance entirely — can the process be redesigned to avoid it?

2

Substitution

Very effective

Replace with a less hazardous substance or form (e.g., water-based instead of solvent-based).

3

Engineering Controls

Effective

Enclose the process, use local exhaust ventilation, or automate to reduce exposure.

4

Administrative Controls

Moderate

Job rotation, reduced exposure time, permits to work, restricted access.

5

Personal Protective Equipment

Least effective alone

Respiratory protection, gloves, goggles, chemical-resistant clothing as a last line of defence.

Storage, Labelling, and Compatibility

Storage Requirements

  • Store in original containers with intact GHS labels
  • Separate incompatible substances (e.g., oxidisers from flammables, acids from alkalis)
  • Provide bunding or secondary containment for liquids
  • Ensure adequate ventilation in storage areas
  • Limit quantities on the shop floor to daily needs
  • Keep flammable stores away from ignition sources
  • Control access — particularly for toxic or highly hazardous substances

GHS Labelling

The GHS (Globally Harmonised System) label must include:

  • Product identifier (name/code)
  • Supplier name and contact details
  • Hazard pictograms (skull/crossbones, flame, exclamation mark, etc.)
  • Signal word (Danger or Warning)
  • Hazard statements (H-statements)
  • Precautionary statements (P-statements)

Never remove, deface, or obscure a GHS label. Decanted substances must be relabelled.

Training and Information

Workers must receive adequate information, instruction, and training before working with hazardous substances. "Adequate" means genuinely understood, not just a signature on a form. Training should be:

Task-specific

Relevant to the actual substances and tasks the worker performs — not generic.

Comprehensible

In a language and format the worker understands, with time for questions.

Documented

Record who was trained, on what, by whom, and when — and keep the records.

Refreshed

Repeated when substances, tasks, or controls change, or at defined intervals.

Workers should know: what the substance is, what the hazards are, how to use it safely, what controls are in place and why, what to do in an emergency or spill, and where to find the SDS.

Records You Must Keep

Good records protect your workers and demonstrate compliance to regulators and insurers.

Substance inventory

What hazardous substances are on site, where they are stored, and in what quantities.

Safety Data Sheets

Current SDS for every hazardous substance. Check for updates at least every 3 years or when the formulation changes.

Hazardous substance assessments

Written assessment of the risks and controls for each substance or group of substances used in a task.

Exposure monitoring records

Atmospheric monitoring results where WELs or OELs may be approached. Keep for 5 years (40 years for carcinogens).

Health surveillance records

For workers exposed to substances requiring health surveillance. Keep for 40 years after last entry.

Training records

Evidence that workers have received adequate information, instruction, and training on the substances they use.

Incident and near-miss records

Chemical spills, releases, exposures, and near-misses, including corrective actions taken.

Manage All Your Hazardous Substances in One Place

EHS Genesis Chemical Management gives you a central register of hazardous substances, SDS version control, linked hazardous substance assessments, and training records — all connected to your incident data.