A respiratory protective equipment is meant to protect a person against inhalation of hazardous substances present in the atmosphere of his/her workplace under forms like solid or liquid aerosols or gases or steams.
The user of a respiratory protective equipment must know the nature of the risks (composition and concentration of the toxic substances) present in the atmosphere in which he/she should work on one hand, and the performances and operating limits of the respirator on the other hand. It’s important to take into consideration the time during which the respiratory protection must be ensured as well as the physiological load (respiratory rhythm) of the user in order to select an adapted respirator with the right autonomy.
OEL: The Occupational Exposure Limit values are the levels of toxic contaminants to which an unprotected worker may be exposed during a given period without adverse health effects.
TLV: the Threshold Limit Value (for exposure to a 15-minute interval).
European norms per product type
EN 136:1998 = Full-face masks
EN 140:1998 = Half masks and quarter masks
EN 143:2000/A1:2006 = Respiratory protections – devices withparticle filters
EN 149:2001+A1:2009 = Particle filtering half masks
EN 14387:2004+A1:2008 = Gas filters and combined filters
EN 14683:2005 = Surgical masks
DISPOSABLE HALF MASKS AGAINST PARTICLES:
• These protectors are covered by the European Standard EN149:2001 + A1:2009.
• They are totally or mostly made in the filtering material itself and are divided into several categories: FFP1, FFP2, FFP3.
Description: Low filtering capacity
Protection against aerosols: 4 X WEL 80% of the aerosols filtered
Protection: Protections against non-toxic solid and liquid aerosols. Protect typically against calcium carbonate, china clay, cement, cellulose, sulphur, cotton, flour, carbon, ferrous metals, vegetable oils.
Area of use: Textile industry, craft industry, metallurgical industry, mining industry, underground civil engineering, woodwork (strong woods excepted).
Description: Medium filtering capacity
Protection against aerosols: 10 X WEL 94% of the aerosols filtered
Protection: Protections against low toxic solid and liquid aerosols. Protect, for axample, against calcium carbonate, china clay, cement, cellulose, sulphur, cotton, flour, carbon, ferrous metals, hardwood, glass fibers, plastic, vegetable and mineral oils, quartz, copper, aluminium, bacteria, fungi and mycobacterium tuberculosis (TB), chromium, manganese, nickel, platinum, strychnine, metal dust and smoke, viruses and enzymes.
Area of use: Textile industry, craft industry, metallurgical industry, mining industry, underground civil engineering, woodwork, welding, melting, metal cutting, hospitals, laboratories, medical
Description: High filtering capacity
Protection against aerosols: 50 X WEL 99% of the aerosols filtered
Protections against toxic solid and liquid aerosols. Protect, for example, against calcium carbonate, china clay, cement, cellulose, sulfur, cotton, flour, carbon, ferrous metal, hardwood, glass fibers, plastic, vegetable oils and mineral oils, quartz, copper, aluminium, bacteria, fungi and mycobacterium tuberculosis, chromium, manganese, nickel, platinum, strychnine, metal dust and smoke, viruses and enzymes.
Area of use: Textile industry, craft industry, metallurgical industry, mining industry, underground civil engineering, woodwork, welding, melting, metal cutting out, hospitals, laboratories, medical controls, pharmaceutical industry, toxic waste treatment, batteries making (Ni-Cad).
Filters of masks with cartridges
protect from gases and toxic vapours.
Longevity test of a gas filter
The longevity of a gas filter is measured by outputting trial gas up to 30 L/min, that is to say the volume of air an average-build person breathes per minute, while doing an average-tough work. The longevity can also roughly be calculated bringing the concentration in-site with the minimum penetration time that is required for one type of filter.
Filter type A:
Area of use: Gases and vapours of organic compounds at boiling point > 65 °C.
Examples of specific hydrocarbons: toluene, benzene, xylene, styrene, turpentine, cyclohexane, carbon tetrachloride, trichloroethylene. Some solvents are often used in the form of mixtures, for instance solvents from benzene, mineral essence, mineral turpentine, white spirit, naphtha solvent. Other organic compounds: dimethylformamide, phenol, furfuryl alcohol, diacetone alcohol. As well as some raw materials raw materials and plastic additives, such as phthalates, phenolic resins, epoxidic plastics and polychlorobiphenyls in the form of PCB isomers.
Filter type AX:
Gases and vapours of organic compounds at boiling point < 65 °C
Filter type B:
Inorganic gases and vapours
For exemple: sulphide dioxide, chlorine, hydrogen sulphide (H2S), hydrogen cyanide (HCN), hydrochloric gas (HCI), cyanide compounds, phosphorus and phosphoric acid.
Filter type E:
Organic acids, acid gases
and in general gaseous acids, nitric acid,
propionic acid, formic acid.
Filter type K:
Ammonia and its organic derivatives
organic amino such as methylamine, ethylamine, ethylenediamine, diethylamide.
Filter type P:
Particles, solid and liquid aerosols
Filter type Hg:
Filter type No:
Nitrous vapors and nitrogen dioxide
Filter type Co:
protect from solid and liquid particles such as dust, smoke, welding smoke, mist, microorganism and radioactive particles.
Particle filter longevity
• The filter does not wear out, but it gets blocked because of the particles and humidity that result from the increased resistance to respiration.
• Against the radioactive matters and microorganisms, a particle filter should be used only once.
• A particle filter must be changed when breathing becomes painful.
Types of particles
• Dust: solid particles transported by air and generated during the treatment of organic and inorganic matters. They can be composed of mineral, coal, wood or cereals such as diverse fibres (asbestos, silicate, fibreglass, etc…).
• Smoking gases: metallic particles generated by the cooling of an evaporated metal and its oxidation when in contact with the oxygen in the air. Smoking gases from lead oxide, for instance, are produced from lead melting. Ferric oxide gases are produced while soldering.
• Smokes: thin particles of coal and soot that integrate liquid droplets.
• Fogs: droplets transported by air, made up of a fluid scattering in the air, in the form of thin particles.
Examples: oil fogs caused by metal machining, at the moment of cutting or grinding.
• Micro-organisms: for instance, bacteria, virus, spores.
• Radioactive particles: are produced by radiation.
Combined filters stop both gases and vapours, as well as particles. First, the air crosses the elements that filter particles, then those that absorb gases. The filtering element stops the spread particles such as paint droplets. Liquids spraying requires the use of combined filters.
• Full-face masks cover the forehead, nose, mouth and chin and have an ocular part; their features are described in the European standard EN136.
• Half-face masks cover the nose, mouth and chin and are described in the European standard EN140.
• To wear a face mask like a full-face or a half-face mask, it is necessary to make sure that the sealing surface is completely continuous to the face. Men must be correctly shaved and any interposition of hair, beard, or glasses temples must be avoided (otherwise the assigned protection factor will be reduced).
• Filtering cartridges for the masks comply with the European standards EN141 and EN14387 (antigas and combined filtres) and EN143 (anti-aerosols) and are labelled with colour-codes according to the European standards and types of filtration:
1 = low capacity,
2 = medium capacity,
3 = high capacity.
• Never use the filtering masks in
atmospheres where the oxygen content is
lower than 17% Vol.