Published: 21st Oct 2013
Making the right RPE selection
Andrew Watson guides us through the use of respiratory protection.
At the very start I should make it clear that providing respiratory protective equipment (RPE) should, like all personal protective equipment (PPE), be a last resort. The hazard that the worker is being protected against should if possible be eliminated or, if elimination is not possible, should be controlled to minimise the risk. This requires a risk assessment to be undertaken. Only when it has been shown that the hazard cannot be eliminated or controlled to a satisfactory level should RPE be considered.
Issuing PPE to a worker may provide them with protection from serious injury and illness, but in the majority of cases this will provide protection against minor cuts and bruises. RPE, on the other hand, will almost certainly be required to provide protection against the risk of very serious injury and illness, which may not become apparent in the short term. RPE provides protection to our breathing mechanism, which is essential for life.
RPE can be divided into two main categories:
Respirators (filtering devices) - These make use of filters to remove contaminants from the air being breathed and are either powered or unpowered Breathing apparatus - This makes use of an independent supply of air suitable for breathing RPE will be required:
• When the risk of exposure to respiratory hazards remains in the workplace following the introduction of control measures • While the employer is implementing effective control measures • In emergency circumstances • For short term or very infrequent periods such as during maintenance work, where controls would not be reasonably practical to implement
The Health and Safety Executive (HSE) in the UK suggests that around 5.5 million employees could be at risk of a respiratory disease in the workplace.
I joined a coal mining industry that had an obvious need to provide its employees with respiratory protection in the form of both types of RPE. As a mine worker, airborne dust protection was necessary and was provided by various types of filtering devices. I also required a filter self-rescuer to provide protection to allow escape from toxic and noxious gases such as carbon monoxide, which is sometimes found in the underground environment. As a mines rescue worker, the use of breathing apparatus was a prerequisite to provide protection against toxic and noxious fumes and gases and/or the effects of an oxygen deficiency in the atmosphere.
The coal mining industry began the process of mechanisation to increase production in the early 1950s. This increase in mechanisation (cutting coal) led to an increase in the production of airborne coal and stone dust. In those early days, the dust hazard was not effectively controlled and no protection was provided to the miners. This led to an increase in illnesses such as pneumoconiosis and silicosis.
When I first joined the industry in the 1970s, the industry had introduced measures to control and minimise the production of dust. This was mainly through dust suppression techniques such as water spraying. Realising that they could control (not to a satisfactory level), but not eliminate the dust hazard, they also made RPE available to the miners in the form of filter dust masks - both disposable and reusable.
Initially dust masks were not readily accepted by the ‘macho’ mineworkers, but through perseverance of mine management and supervisors and the education of the mine workers, they are now accepted as the norm within the industry. The UK coal mining industry is now without doubt a world leader in the methods used to protect its workers from the hazard of dust, both in the way it monitors the hazard and in the control measures utilised to minimise the risk.
The industry has also had some hard and costly lessons about the need to provide RPE to its workers.
During the early hours of the morning on September 26, 1950, a damaged conveyor belt caught in a machine at Cresswell Colliery, causing the motor to overheat and catch fire with 80 men trapped beyond the flames. They all perished as a result of the fumes and smoke generated by the fire. They carried no protection against such an atmosphere.
In September 1959, 47 men lost their lives in a coal mine near the village of Auchengeich, Scotland, when a faulty fan purifying the air in the colliery caught fire due to an electrical fault.
The men died sitting in manriding cars waiting to be transported out of the mine.
The development of filter self-rescuers, which would have protected the miners in both of these incidents, began in the 1920s. They were first introduced in German mines on a large scale in the early 1950s, following a disaster which occurred in 1947 at Grimberg Colliery.
They were made compulsory in the German mining industry in 1957 - two years prior to the Auchengeich disaster.
In 1953 UK trials began with filter self-rescuers and their introduction into the mines began in 1967, with them becoming a condition of employment for all underground miners in 1968.
There is evidence from around the world of self-rescuers being removed by mine workers due to them being uncomfortable to wear, resulting in the death of these miners. This was put down to poor training in the use of the RPE and a lack of awareness regarding the inability to use RPE in the event of a fire.
As you can see, for some considerable time industry in the UK has had extensive knowledge and experience of the need to provide the necessary control measures and RPE to protect its workers from respiratory hazards. Unfortunately, there is also a great deal of evidence of the consequences when these controls are not applied and RPE is not provided.
The HSE in the UK estimates that there were 12,000 deaths from 2009 to 2010 and another 12,000 deaths from 2010 to 2011, which resulted from the long term exposure of workers to occupational respiratory hazards.
Some of the reasons for these unacceptable death rates are as follows:
• Non existent or poor training in the use of RPE • The use of generic rather than specific training in the use of RPE • Poor selection, storage, maintenance and use of RPE • Lack of awareness of and concern for the hazards and risks associated with dust, fumes and gases • Lack of enforcement of the use of RPE by employers • Poorly fitted RPE • Incorrect use of RPE
As already stated, prior to considering the use of RPE, efforts should be made to eliminate the hazard or control it to an acceptable level. Only when these actions have been taken and they have been proven not to be capable of reducing the risk to an acceptable level should the use of RPE be considered.
Correct selection of RPE
The RPE must obviously provide effective protection from the respiratory hazard for the worker - it must be both adequate and suitable.
To ensure the correct RPE is selected, those involved in the selection process will require the following information:
• Identification of the hazard to be protected against • The safe amount (exposure level) of the hazard acceptable (legal) in the atmosphere • The hazard’s form, i.e. gas, fume, vapour or particle • The nature of the work to be carried out - is it regular and repetitive, remedial or emergency work? • Other requirements such as other PPE - remember the combination of a face mask, safety glasses, spectacles and/or noise protection
If the hazard in the atmosphere is, or could be, life endangering such as oxygen deficient or a toxic/noxious gas vapour or fume, then breathing apparatus will be the selected and necessary RPE.
Selecting a respirator
It is a basic requirement that the respirator type should be specific to the identified hazard, to ensure that the correct filter material is able to remove the hazard from the air breathed by the wearer. To this end respirators can be divided into two types: either a particle filter, which includes dust, fibres, smoke and fumes, or alternatively a gas/vapour filter.
It is very important to remember and note that a particle filter will not provide any protection against a gas or a vapour and equally a gas or vapour filter will not provide protection against particles. In some cases there will be a need for a combination of filters to be supplied to protect workers effectively.
To assist those selecting the correct RPE (filter device) each is given an assigned protection factor (APF). The APF is in numerical form and gives an indication of how much protection the RPE can and will provide the wearer. An example of how this works is that if the RPE supplied to the worker has an APF of ten, provided the RPE is fitted correctly and used as required, this will reduce the wearer’s exposure by a factor of ten. In simple terms, the RPE will reduce the quantity of the hazardous substance breathed by the wearer from 100% to 10%. If the RPE has been selected correctly this will be a safe level for the wearer.
Those involved in the selection of RPE must have an understanding of the following terminology:
• Workplace Exposure Limit (WEL) • Safety Data Sheet (SDS) • Time Weighted Average (TWA)
An example of how all of this comes together within the RPE selection process is as follows:
The substance is a solvent, Toluene, see SDS for safe levels.
There is a measured concentration of 350 ppm (parts per million) in the workplace over an eight hour TWA.
Toluene has a WEL of 50ppm.
The APF to reduce the Toluene levels to the WEL is 350/50, which equals seven.
In selecting the correct RPE, in this example select one with an APF above seven.
Don’t forget that if there is more than one hazard present in the workplace those selecting the correct RPE must determine the required protection factor for each hazard and select RPE based on the highest protection factor.
In deciding adequacy and suitability, the following tables may be useful.
The following sections outline factors to consider related to the wearer, the task and the work environment that may impact on safety.
Does the wearer:
• Have facial hair? Beards, in particular, prevent a seal between the face and the RPE • Have any pre-existing medical conditions? • Require spectacles or contact lenses? • Require other PPE?
When planning RPE requirements for the task, consider the:
• Work rate for the completion • Wear time of the RPE • Visibility requirements
The work environment itself will also impact on risk; for example, will the environment be hot and humid? You should also consider the physical dimensions of the work space. If operations are conductedin a confined space, this introduces specified risk and the necessity to comply with confined space regulations.
The effective use of RPE in the workplace
For RPE to be utilised as an effective control method, it must be recognised as a normal procedure in the workplace. Its use needs to be enforced rigorously by management and supervisors. More importantly, it must be accepted by the workforce as being necessary and effective in ensuring their safety from illness and injury. It should be used, maintained and serviced as required and defined by the manufacturer, and effective and adequate training should be provided to the wearer.
The best way to achieve effective use is through the involvement of the wearers in the RPE selection process. This is especially prevalent where there is a choice of adequate and suitable RPE available. Manufacturers should remember that what is comfortable and effective for one wearer may not be as comfortable and effective for another.
It is also very important that wearers of tight fitting facepieces undertake and pass a face fit test specific to the RPE device to be used. The test should be repeated periodically and definitely following changes in circumstances such as an illness, facial injury, weight gain or weight loss.
In the case of RPE that requires a tight fitting seal between the wearer’s face and the RPE, a check of the effectiveness of this seal should be carried out on every occasion when the RPE is to be used. This can simply require the wearer to cover the filter or inhalation valve with their hand and then attempt to breathe in. If the seal is effective the wearer will experience the mask being ‘sucked in’ towards the face. The wearer should then be able to hold their breath and the facepiece should remain in place without requiring additional support. The manufacturer of the RPE should provide information on performing this check.
As with all forms of PPE, pre-use checks on RPE are very important in ensuring the effectiveness of the devices. In the case of breathing apparatus this requirement would be very obvious to the wearer, but it is equally important in respirators. During face fit testing I have seen examples of bad practise by wearers, such as the nose bridge on disposable RPE not being adjusted to ensure a proper seal, straps not being tightened properly or in some cases not being used at all, airlines not being checked to ensure they are connected properly, and powered respirators being used with inadequate power supply (battery life).
On most occasions I find that training is provided at the upper end of PPE use, such as for breathing apparatus, where the hazard and risks are very obvious and would normally have an effect in a short exposure time. The content of this training has, on occasion, not been up to the necessary standard. At the lower risk end of PPE where a long term exposure, e.g. to dust, would be required prior to the hazard and risk affecting the worker, training ranges from good to poor or even non existent.
Everyone who is involved in selecting, storing, using and maintaining RPE requires training prior to doing so. The content of the training should, as a minimum, include the following:
• The limitations of the RPE • The hazards, risks and exposure that the RPE is protecting against • The types and categories of RPE available • How the RPE provides protection • Why fit testing is required • How to carry out pre-use checks on the RPE • How to use the RPE operationally • The maintenance required on the RPE and at what intervals • After use cleaning, maintenance and testing • Storage • Action to be taken, such as reporting, if RPE is found to be faulty • Employer and employee responsibilities • Examples of good and bad practise when using RPE
Maintenance of RPE
Other than when disposable RPE is utilised, the maintenance and testing of RPE is required to ensure the effectiveness in providing continuous protection to the wearer. Testing and inspection should be carried out monthly as a minimum - this is a legal requirement if RPE is used regularly. Maintenance should be carried out as defined by the manufacturer. If the RPE is not used regularly it should be tested and inspected at three monthly intervals as a maximum.
Good practise and legal responsibility dictate that the following should be adhered to when maintaining RPE:
• Follow the manufacturer’s instructions • Use the manufacturer’s parts • Only competent persons should carry out the work • Keep records
RPE should be stored away from direct sunlight to prevent deterioration of the rubber components, and in such a manner that the RPE is not being distorted -follow the manufacturer’s instructions. Always ensure that the RPE is cleaned prior to storage. This prevents contamination of the storage area. The RPE should be readily available to the wearer.
The following are brief descriptions of bad practise witnessed in my career. I have encountered:
1. A store man who would open the cylinder and activate the positive pressure on an RPE set when issuing it, maximising the chance of a high pressure leak before the RPE had even arrived at its required destination.
2. A company that mixed up training model RPE with the real models and issued the training models for use by workers. This only came to light when the training models were returned to the manufacturer for maintenance.
3. A company that stored the RPE in tight boxes in direct sunlight and was surprised that the rubber components deteriorated and could not provide effective protection to the wearer.
4. A risk assessment being carried out incorrectly. The hazard was an explosive atmosphere for which breathing apparatus provided no protection.
5. A company that provided no training in pre-use checks and coupling up procedure for breathing apparatus. The end result of this, fortunately during a mock emergency, was that several workers donned breathing apparatus and due to the urgency created by the mock, deployed without opening their air cylinder valves. Instead of providing the solution to the simulated problem, they created an additional problem by themselves becoming casualties.
The use of RPE is widespread and the incidence of illness and injury is far greater than it should be if proper controls were being implemented. The resulting levels of illness and injury are unacceptable. The use of RPE needs to be controlled by effective hazard identification, risk assessment, management and supervision. Those who are required to use RPE need to be involved in the selection of adequate and suitable RPE. Effective and proportionate training needs to be provided for the wearers - they need to understand the implications of not wearing the provided RPE or of not using it correctly.
There is no reason why an effective RPE management system cannot be implemented if:
• Managers, supervisors and those who are required to wear RPE have the required knowledge and understanding of respiratory risks
• Hazard identification and risk assessment is carried out effectively to ensure that correct, suitable and adequate RPE is supplied and utilised
• A culture of using RPE as required is cultivated
• Communication on the subject of RPE between managers, supervisors and workers is encouraged
• Poor practise is not tolerated
• Training is provided and is effective at all levels of RPE use
• All involved in the selection and use of RPE remain competent
Published: 21st Oct 2013 in Health and Safety International