Respiratory protective equipment [march 2011]

Published: 10th Mar 2011

Many workers are employed in jobs where they are potentially exposed to respiratory hazards. For example, it has been estimated that in the UK alone, about 5.5 million employees could be at risk.

Exposure to respiratory hazards can cause ill health or even result in fatal diseases. The risk is not always to the lungs and respiratory passages. Substances that are toxic to other parts of the body can also enter the body via the lungs.

Hazard control

Ideally, as with other workplace hazards, potential exposure to these substances should be controlled at source, for example by:

• Changing the process which uses them to avoid the exposure altogether

• Replacing them with different (safer) materials

• Installing ventilation systems to remove the hazard

Measures such as these should always be the priority. However, in many workplaces this is often not possible. As a result, employers must therefore find other solutions in such workplaces to protect their workforce.

One option, which is often adopted by employers, is for them to provide their workers with respiratory protective equipment (RPE). Even where other measures are available, employers often use RPE to supplement these, perhaps as a temporary measure when systems are being developed, or at times of increased risk.

Again using UK data, one survey has suggested that more than half of employers asked indicated that they provided RPE for at least some of their employees. However, this often does not solve the problem, as the same research also suggested that, in many workplaces, RPE was not being worn or, where it was worn, it was not being used properly and effectively.

Appropriate for the job?

To start with, if RPE is to provide suitable protection at all, it is clearly essential that the right sort of RPE is selected. Consideration must be given to the nature of the hazard for which it is required. For example, different types of RPE are needed for dusts than for chemical vapours and RPE designed to protect against one might not work against the other (although you can get some which will do both).

Once the right type of RPE has been identified, depending on the nature of the hazardous material, details of the extent and nature of the hazard will determine the level of protection needed. For example, in Europe there are three classes of RPE for dusts or particles, providing different levels of protection based on the proportion of dust they will usually filter out or allow through (filtration efficiency). As those classes of RPE providing a higher level of protection can sometimes be bulkier or heavier than others, overprotection (using a higher performance device than needed) can sometimes increase discomfort and disability and should be avoided when possible.

However, these technical details, although important, are only part of the problem. This article considers the issues which remain once a need for RPE has been identified and the correct type and class of RPE has been selected and provided - the Human Factor.

Hazards of non compliance

As with other forms of PPE, to be at all effective, the worker must be willing to wear the RPE provided; it must fit him (or her) correctly; it must not interfere with other equipment or clothing and it must be correctly worn when needed. Incorrectly worn RPE will provide little or no protection against the hazard.

There is a lot of evidence that there are potential problems with these requirements. Studies have demonstrated that:

• Workers are often reluctant to wear RPE at all (for a variety of reasons)

• RPE does not always fit the intended wearer properly

• RPE sometimes clashes with other PPE worn by the employee or gets in the way when they are working

• Even when they seem to be wearing their RPE, workers do not always wear it correctly

As a result of these factors, the health of these workers is being put at risk.

It goes without saying that if an individual does not wear their RPE at all, then they will not get the intended protection against the hazard and their health will be at risk as a result. However, incorrectly worn RPE can be equally ineffective - and could create additional, greater risks if the workers assume that they are protected and don’t take so much care in avoiding creating or breathing in dusts or other hazards in the first place.

Choosing the right equipment

Reference is often made to the ‘inward leakage’ of RPE. In reality the masks themselves rarely actually leak and studies have shown that it is dust or other materials passing between the RPE and the face of the person which accounts for most of this ‘leakage’.

To provide the correct, effective level of protection and not leak, mask-type designs of RPE (rather than those designed around a hood of some description) rely on maintaining a good, close fit between the mask itself and the face of the wearer. Without that fit the RPE will not work properly.

With RPE it is certainly not the case that ‘one size fits all’. People come in many shapes and sizes, and differences in face sizes and shapes will mean that the same mask is unlikely to fit everybody. This is especially the case with female workers and with employees drawn from populations which are traditionally physically smaller (or larger) than the mask was designed for.

Thus, designs of RPE intended for European workers might not fit workers from some Far Eastern countries. Small faces, chubby faces, ‘sharp’ noses or chins can all be facial features which make it harder to get RPE to fit properly.

Face fit testing, a requirement for some classes of RPE in the UK, can provide some reassurance over fit, although it should be remembered that this testing will only show that the RPE can fit correctly and was fitted correctly during the test, not that the worker in question will necessarily fit and wear it correctly at work on a daily basis.

Other considerations

Apart from facial anthropometry (shape and size) other facial characteristics can also influence the extent to which RPE provides effective fit and protection to the worker. As stated earlier, many types of RPE rely for their effectiveness on a close fit between the mask and the skin of the face.

Facial hair will impair this fit and allow contaminated air to leak into the breathing zone, reducing the protection provided. Ideally, beards or stubble should not be allowed but, where there are perhaps ethnic or religious reasons for retaining beards, other forms of RPE must be provided instead (such as air-fed hoods). RPE can sometimes clash with other items of PPE, or with an individual’s clothing or other personal effects. For example, sometimes it is difficult to wear both RPE and eye protection at the same time.

Either one will stop the other from being worn correctly and not therefore providing complete protection. Another commonly reported problem, particularly with those types of RPE where the mask is made from the filter material (filtering facepiece RPE), is for warm, moist exhaled air from the wearer to pass out through the RPE and make glasses mist-up, making it difficult for the wearer to see and do their job.

This could result in the worker removing their RPE or glasses altogether at times, thus exposing themselves to possible health risks. Using a type of filtering facepiece RPE fitted with an exhalation valve can help moist exhaled air to escape and reduce this problem.

Securing a good fit

Do consider the nature of the work to be carried out while wearing the RPE. It is unrealistic to expect a worker to wear close-fitting RPE for long periods (hours) without a break. In the UK, a maximum of one hour is recommended. In addition, heavy physical work will make the breathing resistance of such RPE more uncomfortable (and therefore less acceptable).

Correct fitting of the straps of close-fitting RPE is an essential part of ensuring a good fit. In some groups of people, items such as turbans or large knots of hair can interfere with the straps and either can make it harder to get a correct fit or increase discomfort for the wearer as a result. Again, problems such as this might result in the worker not using their RPE.

Hazard awareness

Convincing workers of the need to wear RPE and to tolerate any minor discomfort or disability where this cannot be avoided is essential, but not always easy.

Firstly, the workers need to appreciate that there is a hazardous substance present. If they cannot see the hazard or its effects are not felt immediately this might be difficult.

A dust, vapour or other material which irritates the throat and makes a person cough is more likely to convince that person to wear RPE than one where any effect is not so obvious. A good example of this is asbestos, where the levels of airborne fibres are unlikely to be enough to make a person cough and the effects of breathing the fibres into the lungs will not become apparent until 15-20 years after the exposure. This might lead to an employee not considering there to be a real risk and failing to wear their RPE.

Secondly, even where they can see or smell the hazard, the workers need to believe and understand that their health might be at risk from it. Not everybody is affected to the same extent by a hazardous substance.

In the same way as most smokers will tell you that they know someone who has smoked 40 cigarettes a day for 20 years and is (apparently) unaffected, many will know a fellow worker who has done the same job and worked with the hazard for years without any ill-effects.

Unfortunately, although this might well be true, we cannot usually identify those most likely to be made ill - until they become ill. We must therefore protect all of the workforce, rather than find out the hard way which individuals are going to be affected.

Understanding the benefits

Hazard awareness and risk perception are, however, only part of the Human Factor. A number of studies have explored the reasons workers give for not wearing RPE, as well as not considering themselves to be at risk.

• The need to be clean shaven can make some employees reluctant to wear RPE masks at all (or they can ignore this requirement and wear the RPE over stubble, making the RPE less effective). Clearly, religious or cultural grounds for not shaving are different to personal preferences and must be taken into account

• Wearing a facemask can reduce the rate of sweat evaporation from the facial area covered by the RPE and, especially in hot climates, will tend to make the RPE hot and uncomfortable to wear

• Wearing RPE can impair verbal communication - either any talking necessary to carry out the job or chatting between friends

• RPE can sometimes be a bit uncomfortable, especially if it isn’t fitted very well or is too loose (or too tight). This can make it chafe or can allow gritty dusts to get between the mask and skin causing soreness

• Some types of RPE can be quite bulky and can get in the way, particularly when working in tight spaces

• Breathing through any filter will impose some resistance to breathing. Although the manufacturers do make this as low as possible (and this is tested when

RPE is certified for sale) it can get worse as the filter becomes clogged with dust. The fact that this dust would otherwise have gone into their lungs is often forgotten by the worker

Sometimes it has to be recognised that the ‘load’ or ‘discomfort’ felt by the wearer is the price which has to be paid for protecting their health. Self-contained breathing apparatus, with a heavy cylinder of compressed air, is perhaps the best example of this. In such cases it becomes more important than ever to ensure that the workers appreciate and understand the risks of not wearing RPE so that they will put up with, if not accept, a degree of discomfort.

It is sometimes possible for the problem to be reduced or removed by providing the wearer with a different style or type of RPE. For example:

• Single-use (disposable) RPE masks with built-in filters can be lighter to wear than designs which are reusable and fitted with replaceable filters while giving the same potential level of protection (although they can work out more expensive)

• Designs of RPE with a fan and hood (rather than those with a close-fitting mask) do not need the wearer to be clean-shaven and can be cooler to wear (although they are likely to be bulkier and can be considered to be noisy)

• RPE providing protection against gases and vapours can be fitted with smaller and lighter cartridges - although these will need replacing more often than larger sizes as they get exhausted, to maintain the desired protection

• RPE should be replaced (disposable) or filters changed on a regular basis

Finally, once the correct RPE has been provided, in a suitable and acceptable form, it is important not to forget issues such as storage and maintenance requirements.

• If disposable styles are used then arrangements must be made to dispose of used RPE safely, especially if the hazardous substances involved might cause harm to others handling the waste, or to the environment

• Storage facilities are required, either for a supply of replacement disposable RPE or for reusable RPE when not being worn

• Reusable RPE will need to be cleaned and checked for any damage, filters will need to be replaced periodically

• With powered RPE, batteries will need to be re-charged or replaced and there will be further maintenance requirements

In conclusion:

• It is always best to use means of reducing any respiratory hazard other than RPE (e.g. reduction at source) whenever practicable to do so

• Employers must make sure that the RPE chosen is of the right type and provides the right level of protection for the hazard in question (avoiding overprotection as well as underprotection)

• Once the right selection has been made it is important not to forget the Human Factors

• Workers need to understand and appreciate the hazard they might be exposed to and the potential risks to their health associated with not wearing the RPE provided

• Where a design of RPE is provided which, to work correctly, relies on being tight-fitting, then it is essential to ensure that the particular design provided fits each wearer properly. It will probably be necessary to have more than one design available to be sure of this

• If tight-fitting RPE is to work properly the workers required to wear it must be clean-shaven. If this cannot be ensured, or is not possible, then a different design of RPE will be needed

• In choosing a type of RPE, consideration should be given to any other PPE which might be worn, or to other clothing, equipment and work factors where a clash with the RPE might arise

• Work factors, such as the duration of exposure between breaks or the heaviness of any physical work should also be taken into account

• Involving the workforce in the selection process can help to improve acceptance of the RPE

• To be effective, not only must the right type of RPE be selected, but those potentially exposed to the hazard must wear it, and wear it properly - don’t forget the Human Factors

Published: 10th Mar 2011 in Health and Safety Middle East