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Mandatory signs explained: the blue circle UK guide

What blue circle mandatory signs mean, where to place them, and the full UK pictogram set under BS EN ISO 7010.

By Direct Signs Team · ISO 9001 certified UK manufacturer · Updated April 2026

The short answer

A mandatory sign is a solid blue circle with a white pictogram. It tells you what you must do — wear hard hat, wear hi-vis, wash hands, fire door keep shut. Under BS EN ISO 7010, every blue circle = required action. They are placed at the boundary of the zone where the action is required, mounted at standard interior heights (top edge 1.7-2.2m above floor).

The mandatory pictogram set

BS EN ISO 7010 standardises around 30 mandatory pictograms. The most common in UK workplaces:

  • M001 — Wear safety helmet (hard hat)
  • M003 — Wear hearing protection
  • M004 — Wear eye protection
  • M008 — Wear safety footwear
  • M009 — Wear safety gloves
  • M010 — Wear protective clothing
  • M013 — Wear face shield
  • M014 — Wear head protection
  • M015 — Wear high-conspicuity garments (hi-vis)
  • M017 — Wear respiratory protection
  • M018 — Wear safety harness
  • M020 — Wear safety belt
  • M022 — Use barrier cream
  • Hand wash — wash hands
  • Fire door keep shut — close door
  • Keep clear — keep area unobstructed

When mandatory signs are legally required

Mandatory signs are required when risk assessment identifies a residual risk that requires a specific action — typically PPE. The Personal Protective Equipment at Work Regulations 1992 (as amended 2022) require employers to provide PPE and to communicate where it must be worn. Practical regulations triggering mandatory signs:

  • Workplace (Health, Safety and Welfare) Regulations 1992 — general workplace duties
  • PPE Regulations 1992 + 2022 Amendment — PPE provision and signage
  • CDM 2015 — construction site PPE signage
  • Control of Noise at Work Regulations 2005 — hearing protection at noise action levels
  • COSHH 2002 — respiratory protection in hazardous substance areas
  • Working at Height Regulations 2005 — safety harness signage
  • Fire Safety Order 2005 — fire door keep shut, keep clear

Where to place mandatory signs

The principle: at the boundary of the zone where the action is required, in line of sight of anyone entering. Specific rules:

  • PPE-required zones: at every entry point. Construction site → main gate. Hard-hat zone within a building → at the door to that zone. Ear-protection-required area → at all entry points.
  • Action-at-point signage: "wash hands" sign at the sink. "Fire door keep shut" on the fire door itself. "Use handrail" at the bottom of the stairs.
  • Mounting height: top edge 1.7-2.2m above the floor for standard interior placement.

For the full placement principle, see our placement guide.

Combined and bespoke mandatory signs

For high-PPE-requirement zones (construction sites, factory floors with multiple PPE requirements), combined mandatory signs are widely used. Examples:

  • "Hard hat + hi-vis + safety footwear must be worn beyond this point" — three pictograms on a single sign panel
  • "PPE required: see notice" — pointing to a fuller list at the entry point
  • Branded versions in company colours with custom wording
  • Multi-language versions for international workforces

Provided the standard blue-circle pictograms are preserved, custom wording and combinations don't break BS EN ISO 7010 compliance.

Materials and lifespan

For indoor mandatory signs (factory floor, warehouse, office): rigid PVC. For external PPE signs at construction sites and yards: aluminium composite. For high-impact or vehicle-yard environments: pressed aluminium. See our materials comparison guide.

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Quick answers

Mandatory sign FAQs

What is a mandatory sign?
A mandatory sign is a blue circle with a white pictogram or text. It tells you what you must do — wear hard hat, wear hi-vis, wash hands, fire door keep shut, etc. Under BS EN ISO 7010, blue circle = "you must take this action."

When is a mandatory sign required?
When workplace risk assessment identifies that a specific action (typically wearing PPE or following a procedure) must be taken to control a residual risk. The Health and Safety (Safety Signs and Signals) Regulations 1996 require mandatory signs where the action cannot be eliminated by engineering controls.

Where do mandatory signs go?
At the entry point or boundary of the zone where the action is required. Hard-hat zone signs at the entrance to the zone, not at the building entrance. Wash-hands signs at the relevant sinks or food prep areas. Fire-door-keep-shut on the door itself.

What's the difference between mandatory and prohibition signs?
Mandatory tells you what you must do (blue circle, "must"). Prohibition tells you what you must not do (red circle with diagonal line, "must not"). Same shape, opposite intent — distinguished by colour and the diagonal line.

Are mandatory signs different in colour from other safety signs?
Yes. The five BS EN ISO 7010 categories: prohibition (red circle with line), warning (yellow triangle), mandatory (blue circle), safe condition (green rectangle), and fire equipment (red square). Each has a distinct shape-and-colour combination.

Can mandatory signs include custom wording?
Yes. Bespoke mandatory wording (e.g. "Hard hat must be worn beyond this point") is widely used. Provided the standard pictogram and the blue-circle format are preserved, custom wording does not break BS EN ISO 7010 compliance.

Do mandatory PPE signs cover all PPE types?
BS EN ISO 7010 has standard pictograms for hard hat, hi-vis, safety footwear, ear protection, eye protection, respiratory protection, gloves, face shield, safety harness, and high-conspicuity garments. For unusual PPE (e.g. specific chemical-resistant suits), a bespoke pictogram is sometimes needed.

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