Manufacturing & Engineering UK-wide

Operate a safe chemical manufacturing site: major-hazard, environmental and explosives controls

A task guide for chemical manufacturers (SIC division 20) on the site-based controls that apply to a working chemical plant. It covers major-accident hazard duties under COMAH, the environmental permit for the installation, dangerous-substance and explosive-atmosphere controls under DSEAR, and the licensing and supply controls for explosives and their precursors.

Guide summary

Check which site-based controls apply to your chemical manufacturing site before you operate. You may need a COMAH safety report, an environmental permit, DSEAR controls, or an explosives licence depending on what substances you hold and what you do.

  • Check if your site has enough dangerous substances to need COMAH controls
  • Apply for an environmental permit before operating an industrial-scale plant
  • Assess fire and explosion risks under DSEAR for all flammable substances
  • Get an explosives licence if you make or store explosives
  • Notify the Competent Authority if you are a lower-tier COMAH site
  • Write a safety report and emergency plan if you are upper-tier COMAH
  • Keep your permit copy on site and show the permit number on waste forms
  • Classify hazardous areas into zones and use safe equipment in each zone
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Related guides in Health & Safety

A working chemical plant carries duties that go beyond the products it makes. The process, the plant and the substances on site all create risk, and the law requires you to control major-accident hazards, hold an environmental permit where your installation needs one, manage dangerous substances and explosive atmospheres, and licence any manufacture or storage of explosives. This guide is for makers of chemicals and chemical products (SIC division 20) putting those site-based controls in place.

Which controls apply depends on what you hold and what you do. A site with qualifying quantities of dangerous substances is caught by COMAH; an industrial-scale installation needs an environmental permit; any site handling flammable or reactive substances engages DSEAR; and only sites that make or store explosives need an explosives licence. Work out which apply to your site, then put each in place before you operate.

The major-hazard, environmental and DSEAR duties are UK-wide, but the regulator differs by nation. For COMAH and environmental permitting the competent authority pairs the health-and-safety regulator with the environmental regulator: HSE with the Environment Agency in England, HSE with Natural Resources Wales in Wales, and the equivalent bodies with SEPA in Scotland and NIEA in Northern Ireland. The explosives regimes below apply in Great Britain; Northern Ireland operates a separate explosives regime, so check the NI position separately if you operate there.

Control major-accident hazards under COMAH

Start here if your site holds qualifying quantities of named dangerous substances. The COMAH regime makes your site a lower- or upper-tier establishment with duties to prevent major accidents — a major-accident prevention policy, notification, and, for upper-tier sites, a safety report and an on-site emergency plan. COMAH is enforced jointly by the health-and-safety and environmental regulators acting as the Competent Authority for your nation.

Hold an environmental permit for the installation

If you run a chemical installation on an industrial scale — producing bulk inorganic chemicals or gases, for example — you need an environmental permit before you operate. The permit requires you to apply the best available techniques and to control and monitor emissions to air, water and land. Apply to the environmental regulator for your nation: the Environment Agency, Natural Resources Wales, SEPA or NIEA operate equivalent permitting regimes.

Manage dangerous substances and explosive atmospheres under DSEAR

Wherever you handle flammable, oxidising or unstable substances, DSEAR requires you to assess and control fire, explosion and similar energetic-event risks. You must classify hazardous areas into zones and select equipment that is safe to use in them. This applies to almost every chemical site, not only major-hazard establishments, and reads alongside your COMAH and fire-safety duties.

Licence the manufacture or storage of explosives

This applies only if you make or store explosives. A licence is required under the Explosives Regulations 2014, with assigned hazard types and separation distances. HSE is the regulator for manufacture and larger stores in Great Britain, with the local licensing authority or police for smaller stores. If you supply high-nitrogen fertilisers or other regulated substances, the controls on explosives precursors and poisons also apply, including reporting suspicious transactions.

Steps to put the site controls in place

Work through the controls in order before you operate. The COMAH safety report, the environmental permit and the explosives licence all take time to obtain, so begin early.

  1. 1

    1. Identify which controls apply to your site

    Confirm whether you hold qualifying quantities of dangerous substances (COMAH), run a permitted installation, handle flammable or reactive substances (DSEAR), and make or store explosives. Most chemical plants engage several of these at once.

  2. 2

    2. Put your major-accident controls in place

    If you are a COMAH establishment, prepare your major-accident prevention policy, notify the Competent Authority, and, for an upper-tier site, produce the safety report and on-site emergency plan.

  3. 3

    3. Apply for the environmental permit

    Apply to the environmental regulator for your nation — the Environment Agency, Natural Resources Wales, SEPA or NIEA — before you operate. Be ready to show how you apply the best available techniques and control emissions.

  4. 4

    4. Assess and zone for DSEAR

    Carry out the DSEAR risk assessment, classify hazardous areas into zones, and select and maintain equipment that is safe for use in those zones.

  5. 5

    5. Licence any explosives activity

    If you make or store explosives, obtain the licence under the Explosives Regulations 2014, and put the precursor supply controls and suspicious- transaction reporting in place where they apply.

  6. 6

    6. Monitor, review and keep records

    Carry out the monitoring your permit and assessments require, review your controls as the site changes, and keep the records. These duties continue for as long as you operate.

What to do next

The COMAH duties, the environmental permit and the DSEAR controls all carry ongoing review, monitoring and reporting obligations, so plan for them as standing duties rather than one-off approvals. To get your products lawfully onto the GB market, read the companion guide on placing chemical substances and products on the GB market. Run the chemical manufacturer compliance checklist before any production run. If you are unsure whether COMAH or a permit applies to your site, confirm it with the relevant regulator before you commit — it is far cheaper to check than to operate without the right controls.

Official sources

Statutory sources and regulators for operating a chemical manufacturing site