Confined spaces, dust-filled shops and other environments that could make the simple act of breathing dangerous are all in a day’s work for industrial workers. While keeping contaminants such as harmful dusts, fog, fumes, mist, gases, smokes, sprays and/or vapors out of the air workers breathe is the first line of defense, proper respiratory protection also is essential. If re-engineering a task or equipment fails to provide a safe working environment, employers must provide appropriate respiratory protection for every employee who might be exposed to harmful contaminants.
General classification of Respiratory Protection Devices
There are two general types of respiratory protective equipment (RPE), based on the principle by which protection is provided to the user. The two types are the following:
- Respirators (filtering equipment) i.e.: filter, gas filter, combined filter, filtering half-mask.
- Breathing apparatus (isolating equipment) i.e.: self-contained breathing apparatus (open-circuit and closed circuit), compressed line breathing apparatus.
Respirators are designed to filter out or clean contaminated air from the workplace atmosphere before it is inhaled by the respirator wearer. Respirators are not designed to be used in atmospheres with oxygen deficiency (concentration of oxygen is below 19%) or where the concentration of unknown contaminants has not been evaluated.
Breathing apparatuses deliver breathable air from an independent source (compressed air vessels, compressed line) to the user. Breathing apparatuses are designed for use in atmospheres with oxygen deficiency (where the concentration of oxygen is below 19%).
General classification of the Respiratory Protective Equipment is as follows:
- Respirators– filter out contamination from the air in the workplace before it is inhaled by the user:
- Filtering respirators:
- Filtering face pieces
- Half mask with filter(s)
- Full-face mask with filter(s)
- Powered/assisted respirators:
- Powered hoods and helmets with filter(s)
- Powered-assisted half mask with filter(s)
- Powered assisted full-face mask with filter(s)
- Breathing apparatuses– provide uncontaminated breathable air from independent source:
- Compressed airline breathing apparatuses:
- Constant flow with any type of face piece
- Negative demand half or full-face mask
- Positive demand half or full-face mask
- Indented line Self-contained breathing apparatuses:
- Open-circuit negative demand full-face mask
- Open circuit positive demand full-face mask
- Closed-circuit full-face mask demand
Filtering face pieces:
These face pieces are often called “disposable respirators". They either entirely or substantially consist of filter material. They should conform to the EN 149:2001 standard and are classified as FFP1, FFP2 and FFP3 to increase filtration efficiency.
There are two types of these respirators i.e.
- Intended to be used for a maximum of a single shift (marked with the letters NR – not reusable), and
- Intended to be used for more than a single shift (marked with the letter R – reusable).
The respirators may incorporate inhalation and exhalation valves or exhalation valve(s) only, or have no valves. Where the filtering face piece has no valves, both inhaled and exhaled dangerous substances can pass through the filter material. An example of the filtering face piece is shown in the picture.
There are also valved filtering half masks to protect against gases or vapors and particles. These devices are “disposable" respirators essentially for use against gases and vapors, but with optional protection against particles. Any gas/vapor filters form an inseparable part of the device; any particle filters maybe integral or separable. Complete devices should conform with the EN 405:2001+A1:2009 standard and are designated according to the filter type used and have the prefix FF. The devices must have both inhalation and exhalation valves. Examples of gas/vapor and combined filters are: FFA1, FFB2P3, FFK1P2. There are also two types of these respirators i.e. those intended to be used for a maximum of a single shift (marked with the letters NR – not reusable), and those intended to be used for more than a single shift (marked with the letter R – reusable).
Filters either entirely or substantially consist of filter material. There are particle filters, gas filters and combined filters.
The particle filters should conform to the EN 149:2001 standard and are classified as P1, P2 and P3 in order to increase filtration efficiency. There are two types of these respirators i.e. intended to be used for a maximum of a single shift (marked with the letters NR – not reusable), and intended to be used for more than a single shift (marked with the letter R – reusable).
The gas filters should conform to the EN 14387:2004+A1:2008 standard and are classified as:
- A - for use against certain organic gases and vapors with a boiling point > 65 °C as specified by the manufacturer,
- B - for use against certain inorganic gases and vapors as specified by the manufacturer.,
- E - for use against sulfur dioxide and other acidic gases and vapors as specified by the manufacturer
- K - for use against ammonia and organic ammonia derivatives as specified by the manufacturer,
- AX - for use against certain organic gases and vapors with a boiling point £ 65 °C as specified by the manufacturer. For single use only,
- SX - for use against specific named gases and vapors as specified by the manufacturer.
Multi-type gas filters - filters which are a combination of two or more of the above listed types, excluding SX, and which meet the requirements of each type separately.
Combined filters - gas or multi-type gas filters incorporating a particle filter according to EN 143:2001.
The protection provided by a class 2 or class 3 filter includes protection provided by the corresponding filter of lower class or classes.
The classification of combined filter(s) includes that of particle filter(s) according to EN 143:2000.
Type AX and type SX gas filters and special filters are not classified.
Facepieces
- Half masks: usually reusable molded face pieces, of rubber or plastic, covers the nose and mouth of the wearer and is held in place with adjustable straps. Air passes through the relevant filter(s) by the wearer’s lung force, or may be supplied by a powered unit or suitable breathing apparatus attached to the mask. The exhaled air passes through an exhalation valve(s). Filters are available for particulates, gases or vapors or as a combination. The mask should conform to the EN 140:1998 standard. An example of a half mask in shown in the picture.
- Full-face masks: reusable devices that cover the eyes, nose, mouth and chin, and seals against the face of the wearer. It is held in place (on the head) with adjustable straps. Air is drawn into the mask either through a relevant filter(s) by the wearer’s lung force, or may be supplied by a powered unit or suitable breathing apparatus attached to the mask. The exhaled air passes through an exhalation valve(s). Most masks have an inner half mask. Some devices may be equipped with a speech diaphragm to improve the quality and clarity of voice communication. The visor provides protection against particulates and gases.