GUIDE TO RESPIRATORY PROTECTION

EN 149 AND RELATED STANDARDS

Respiratory Protective Equipment (RPE) is designed to protect the wearer from breathing in hazardous substances such as dust, mists, vapours, gases, or fumes. In some environments, RPE also supplies clean air where oxygen levels are insufficient.

In the UK, RPE must meet European standards that define the level of protection, the type of hazard, and the testing methods. Selecting the right protection requires a risk assessment of both the hazard and the working conditions.

1 — Identify the Task, the Hazard and the Risk of Exposure

Task — What work are you doing? Cutting concrete, spraying paint, handling chemicals, or working in confined spaces?
Hazard — Dust, vapour, gas, mist, fume, or oxygen deficiency.
Risk — How frequent and long is the exposure? How severe are the health effects?

2 — Main Respiratory Protection Standards

EN 149:2001 + A1:2009 — Filtering Half Masks (FFP1, FFP2, FFP3)

This standard covers disposable filtering half masks (often called “disposable respirators” or “dust masks”). They are classified by efficiency:

Class	Max Total Inward Leakage	Protection Factor	Typical Use
FFP1	22%	4 x Workplace Exposure Limit (WEL)	Low-level dusts (sanding, DIY, light construction)
FFP2	8%	10 x WEL	Moderate dusts, mists, welding fumes
FFP3	2%	20 x WEL	Hazardous fine dusts, asbestos, biological agents, viruses

EN 136 — Full Face Masks

This standard applies to full-face reusable masks made from durable materials.

Provide a high level of protection against gases, vapours, and particulates (depending on filter used).
Face seal and visor protect eyes as well as respiratory system.
Often used in environments with toxic chemicals or high dust concentrations.
Compatible with EN 143/EN 14387 filters.

EN 140 — Half Masks

This standard covers reusable half masks (covering nose, mouth, and chin, but not eyes).

Designed for use with replaceable filters (EN 143, EN 14387).
Lighter and less restrictive than full face masks.
Used in moderate hazard environments where eye protection isn’t required.
Requires regular cleaning and filter replacement.

EN 143 — Particulate Filters

This standard applies to replaceable particulate filters used with half masks (EN 140) and full face masks (EN 136).

Filters are divided into three classes:

Class	Efficiency	Protection Factor	Examples of Use
P1	80%	4 x WEL	Non-toxic dusts
P2	94%	10 x WEL	Moderate dusts, mists
P3	99.95%	20 x WEL	Highly toxic dusts, asbestos, radioactive particles

Filter Code	Colour	Protection	Examples of Use
A	Brown	Organic vapours (boiling point >65°C)	Solvents, paints
B	Grey	Inorganic gases/vapours	Chlorine, hydrogen sulphide
E	Yellow	Acid gases	Sulphur dioxide, HCl
K	Green	Ammonia and derivatives	Agriculture, fertiliser plants
AX	Brown (with marking)	Organic gases/vapours <65°C BP	Specific low-boiling solvents
Combined	Multiple bands	Mixed hazards	Spray painting, chemical handling

3 — Key Considerations

Fit testing: A tight seal is essential — HSE requires face-fit testing.
Filter life: Particulate filters clog over time; gas filters become saturated and must be replaced before breakthrough.
Environment: High humidity, heat, or confined spaces affect performance.
Other PPE: Ensure compatibility with goggles, helmets, and ear protection.

4 — Special Hazards

Asbestos — FFP3 or P3 filters minimum, often full-face.
Biological agents — High-efficiency filtration (FFP3, P3).
Oxygen-deficient atmospheres — Only breathing apparatus (BA) is suitable.
Chemical spills — Gas/vapour filters or supplied air systems depending on substance.

Respiratory protection must always be selected based on a risk assessment and in line with UK HSE regulations. If you are unsure, speak to a safety officer or consult our team for advice.