Published: 10th Apr 2007
Breathing cleaner air ....
The most important defence against respiratory hazards is to control the contamination at source and stop it entering the air in the first instance. This however, does not provide the solution to all circumstances and when it does not it will be necessary to use respiratory protective equipment.
Hazardous substances that can contaminate the air include dust, gases, fumes, mist, vapours, and smoke. Inhaling such contaminants can cause damage to many parts of the body including most commonly the nervous system, lungs, nose and throat. In some cases they can trigger allergic reactions such as asthma when inhaled. Oxygen-deficient atmospheres (i.e. when oxygen concentration in the air falls below 17%), also present an unacceptable hazard.
Occasionally work needs to be carried out in conditions that are described as being Immediately Dangerous to Life or Health (IDLH) and can occur when toxic chemicals, gases or particles are present or when there is a deficiency of oxygen. In such situations, individuals can be quickly overcome, are unable to effect an escape and could suffer severe or irreversible damage.
There are two ways to protect against such hazards. The first is to control the contamination at source and prevent it from entering the air in the first place. This can involve isolating the hazard, enclosing the function that is generating the contamination, ventilating the contaminated area and maintaining these systems to ensure they remain effective. In the situation that the source of contamination cannot be eliminated then the second method of protection is the use of respiratory protective equipment. Whilst this is often considered a last resort it is particularly practical when access to the contaminated area is needed for short periods of time or in emergency situations. Respiratory protective equipment suitable for these types of situations include masks, respirators, air-fed systems and self contained breathing apparatus.
Following the rules
Anyone who comes into contact with hazards affecting the respiratory system should be aware of the need to use the appropriate form of protective equipment and employers certainly must heed the practices laid down in their health and safety policies and those set out in the Personal Protective Equipment at Work Regulations 1992. Specific regulations also exist to address particular issues about personal protective needs. Currently these include The Ionising Radiations Regulations 1999, The Control of Asbestos at Work Regulations 2002 and The Control of Substances Hazardous to Health Regulations 2002 (as amended).
Assessing the risk
Lives can be saved and the health and well being of employees can be maintained by providing effective respiratory protection for workers in contaminated environments.
Many factors determine who should wear respiratory protective equipment as well as how and when they should wear it. For this reason, experts in this field state that one nominated person, usually the safety professional, health and safety or risk manager should make the recommendations on the type and use of respiratory protective equipment.
Such responsibility must be placed in the hands of the professionals who will assess the need for a respiratory protection programme at their workplace. This would involve assessing the general health of those destined to use the equipment, because, in case of breathing related conditions like asthma or reduced lung capacity, this may affect their ability to breathe correctly whilst using the equipment. Following the selection of appropriate equipment, the potential users must be trained in the equipment’s proper use including its capabilities and limitations, how to conduct appropriate fit tests, storage, maintenance, use and disposal of the equipment as well as the understanding of the terminology used in the equipment’s manual. Respiratory protective equipment must also be compatible with other PPE worn or used to prevent its effectiveness being compromised.
If using respiratory protective equipment is the chosen solution for your site or situation then it is important to make sure:
- That the necessary respiratory protective equipment is provided to all those who require it
- It offers adequate protection for its intended use
- Those using it are adequately trained in its safe use
- It is properly maintained and any defects are reported and rectified prior to further use
- It is stored and maintained in the recommended manner between periods of use
What type of respiratory equipment is available?
Generally speaking there are two types of respiratory protective equipment, those that provide an air filtering function and those that are provided with a supply of breathable air. Those that provide a filtering function are not suitable for use in oxygen deficient environments or where the contaminant is unknown. In these instances, respiratory protective equipment that provides a supply of breathable air should be used.
Air filtering respirators:
- The air filtering type range from simple filtering face-pieces to filtering systems incorporating a quarter, half or full face mask, a hood or a helmet. The filtering face-piece is generally a disposable item intended for single shift use to protect against particulates. It is not suitable for filtering gas or vapour
- For the systems that incorporate a mask, hood or helmet the filtering element can be mounted on these items or in some instances, belt mounted. Many of these types of system incorporate a turbo unit to supply the filtered air to the user. These systems can be fitted with particle only filters, gas or vapour filters or combined gas and particle filters
- There are different classes of filter to cater for the variety of size of particulate and/or gas and the end user is responsible for the selection of the appropriate type(s) for the working environment. These systems are generally reusable with just the filters being discarded once filtering efficiency is reduced
- Hoods fitted with appropriate filters are available to aid self rescue from burning buildings
Air supplied respirators:
- Equipment that supplies the user with breathable air can be fed from a number of sources including compressed air lines, cylinders of compressed air or hoses supplying breathable fresh air. The equipment generally includes a quarter, half or full face mask, a hood or a helmet. The compressed air systems will include regulators and safety valves and often the hose supplied systems include a turbo unit. Such equipment can be used in environments where there is a deficiency in oxygen or the contaminant is unknown and thus is ideal for emergency and/or rescue situations or where the contaminant is highly toxic. When compressed air is used it can be part of a self contained system and when used in conjunction with appropriate protective clothing complete isolation from the dangerous environment can be achieved. The drawbacks of such systems are that they are heavy, bulky, hot, cumbersome and their range is limited to the amount of air the user can carry thus their use is generally restricted to rescue situations or short term work with unknown or highly toxic contaminants
- Simplified versions of the self contained breathing apparatus systems are available to provide self rescue systems, such systems providing the user with a defined limited air supply to use during their escape from the hazard
Fit for Purpose
Respiratory protective equipment is expected to be safe and fit for its stated purpose. This minimum expectation is demanded by manufacturers, distributors, legislators and users alike. The industry-wide commitment to responsible manufacturing is supported and governed by a range of standards and regulations such as the European Personal Protective Equipment (PPE) Directive (89/686/EEC).
|Some Standards applicable for respiratory protective equipmentat January 2007 Please note this list does not contain every relevant standard|
|BS 8468:2006 – Respiratory protective devices for use against chemical, biological, radiological and nuclear (CBRN) agents series|
|BS EN 12941:1999 – Respiratory protective devices - powered filtering protective devices incorporating a helmet or hood|
|BS EN 12942:1999 – respiratory protective devices. Power assisted filtering devices incorporating full-face masks, half masks or quarter masks. Requirements, testing, marking|
|BS EN 140:1999 – respiratory protective devices. Half masks and quarter masks. Requirements, testing, marking|
|BS EN 14387:2004 – respiratory protective devices. Gas filter(s) and combined filter(s). Requirements, testing, marking|
|BS EN 143:2000 – respiratory protective devices. Particle filters, Requirements, testing, marking|
|BS EN 149:2001 – respiratory protective devices. Filtering half masks to protect against particle. Requirements, testing, marking|
|BS EN 132:1999 – respiratory protective devices. Definitions of terms and pictograms|
|BS EN 135:1999 – respiratory protective devices. List of equivalent terms|
|BS EN 405:2002 – respiratory protective devices - valved filtering half masks to protect against gases or gases and particles|
|BS EN 403:2004 – respiratory protective devices for self rescue - filtering devices with hood for escape from fire|
|BS EN 1146:1997 – respiratory protective devices for self rescue - self contained open-circuit compressed air breathing apparatus incorporating a hood|
|BS EN 14593-1:2005 – respiratory protective devices - compressed air line breathing apparatus with demand valve - with full mask|
|BS EN 14593-2:2005 – respiratory protective devices - compressed air line breathing apparatus with demand valve - with half mask|
|BS EN 14594:2005 – respiratory protective devices - continuous flow compressed air line breathing apparatus|
How do you know if the respiratory equipment that you propose to use is fit for its intended use? The simple answer is to check that they have been tested against the relevant standards that apply to your country. There may be different standards for different countries so it is worth checking with your national body that is responsible for Health and Safety. Within the EU there is a legal requirement for PPE products placed on the market to be CE marked, indicating that they have successfully been through the EC Type-Examination procedure, and they must have a reference to a Notified Body indicating that there is in place an ongoing annual quality monitoring of the product or of the manufacturer’s registered quality system. The Type-Examination and ongoing quality assessment will have been conducted by a Notified Body, with the product being assessed to the appropriate Harmonised European Standard, or to a Technical Specification deemed by the Notified Body to meet the Basic Health and Safety Requirements of the Directive.
Testing and Certifying Respiratory Equipment
BSI Product Services, as part of the world renowned BSI Group, has been testing and certifying PPE for over 40 years and is a Notified Body for the PPE Directive and more than 16 other Directives. As an independent organisation their impartiality is one of the key strengths affording their clients a real business asset. Expert and experienced staff test and certify respiratory protective equipment to a wide range of standards including British (BS), European (EN) and International (ISO) or manufacturer’s technical specifications.
Typical tests performed include:
- Breathing resistance
- Filter penetration (solids)
- Filter penetration (liquids)
- Total Inward Leakage (TIL)
- CO2 build up
- Dust clogging
- Field of vision
- Mechanical strength testing
- Practical performance testing
- Visor robustness
- Inhalation/exhalation valve tests
- Air supply
- Checking and warning facilities
- Electrical components
- Noise level
- Strength of couplings
- Resistance to collapse of breathing hoses
- Resistance to thermal radiation
- Head harness effectiveness
- Leak tightness
- Cleaning and disinfecting
Where respiratory protective equipment incorporates headwear, eyewear or hearing protection BSI is able to offer an integrated test and assessment service. When the products incorporate electronic devices the necessary additional assessments can be conducted in BSI’s comprehensively equipped Electro Magnetic Compatibility and/or Electrical Safety laboratories thus providing the ability to fully test the multiple varieties of state of the art respiratory protective equipment.
Typical products tested and/or certified at BSI Product Services include:
- Disposable filtering half masks
- Gas and combined filters
- Particle filters
- Filtering quarter, half and full face pieces
- Supplied air (powered) face pieces, hoods and helmets
- Compressed air escape sets
- Re-breather escape sets
- Compressed Air supplied equipment
- Self contained breathing apparatus (SCBA)
- Protective suits with integral respiratory protection
- Escape hoods
- Bespoke products
Health & safety training and guidance
As part of the BSI Group, Business Information offers guidance books and DVDs on a wide range of health and safety issues that affect the workplace. For more information on these please call BSI Customer Services on +44 (0) 20 8996 9001 or visit the website on www.bsi-global.com/healthandsafety.
The 2005/06 Self-reported Work-related Illness survey estimated that there were 156,000 people with “breathing or lung problems” which they believed to be work-related. (Source Health and Safety Executive, UK)
For the safety of you, your employees and your business be serious about safety and provide the best respiratory protective equipment available.
Published: 10th Apr 2007 in Health and Safety International