Maintaining reusable respirators
23 January 2013
Reusable half-face and full-face respirators are a proven
and effective means of ensuring that workers in a variety of
environments receive a clean,safe air supply,but only if they
are correctly maintained, explains Aicha
Modern products are highly versatile and can be fitted with a variety of filters which reduce the wearer's exposure to gases, vapours and particulates, depending on the filter used.
However, respirators will only offer the wearer effective protection, with product working life maximised, if pre-use and post-use checks, care and maintenance, and replacement of consumable parts are carried out at the right times and in the correct manner. Appropriate storage for any periods when products are not in use is also crucial.
Unlike single-use respirators, which can usually be assumed to be intact and ready for use on removal from their packaging, checks should be made by the user before wearing a previously used reusable respirator.
The face piece should be checked for cracks, tears and dirt, while the inhalation valve may also harbour cracks and tears.
While washing may be adequate to remove dirt, it goes without saying that any respirator which has any cracks or tears is likely to offer significantly reduced protection, potentially exposing the wearer to hazardous levels of gas or particulates, and should not be used.
The next step is to check that the head straps are intact and have elasticity.
Respirators whose straps have lost their elasticity are unlikely to offer a snug enough fit around the user's face, potentially leaving gaps through which harmful gases and particulates can pass.
The user should also check that all gaskets are present and then remove the exhalation valve cover to examine the exhalation valve and seat for dirt, cracking or tearing. Once again, any product displaying either cracks or tears should not be used. For both half-face and full-face masks, a variety of spares are available and employers would be well advised to maintain a stock of spares for each product type used on site to allow any repairs to be undertaken immediately. The lifetime of lenses can also be prolonged through the use of peel-off lens covers.
Once the user has satisfied himself or herself on all these points, and the correct filters - either gas or particulate - are attached, the product can safely be worn.
One issue which can significantly impact on the protection offered by reusable respirators is what happens to them when they are removed mid-shift, for example for lunch or a comfort break, and when the user returns and put them on again.
Unfortunately, it is not unheard of for the user to remove the product while still in the hazardous area. This is dangerous enough in itself but the problem is exacerbated if the respirator is then left in the area where harmful contamination can settle on the interior of the product, meaning the next time it is worn, the user is breathing potentially highly toxic air.
Employees should be instructed, therefore, to always don the respirator before entering the affected area and not to remove it until they are well clear.
After use, reusable respirators should be cleaned and, if required, disinfected. The user instructions with the product will contain the cleaning and disinfection requirements. Masks are generally cleaned with a specialist, disposable cleaning wipe or by immersion in a cleaning solution. A soft brush can be used if scrubbing is required. After washing, the product should be rinsed in fresh, warm water and air dried in a non-contaminated atmosphere. Respirators are also sometimes cleaned in a washer.
Once dry, masks should be stored away from contaminants in a clean area, with full face masks stored face-up to reduce the risk of scratches to the lens.
Given variations in usage levels and also in the quantity of gas and particulates being filtered, it is difficult to be prescriptive about the intervals at which the filters should be changed, although a thorough risk assessment will give some indication. As a rule, particulate filters can be used until the user notices they are becoming harder to breathe through, while gas and vapour filters should be replaced before they become saturated, or as a last resort, when the user notices a smell or taste of gas, which indicates that the carbon contained within the filter is saturated. For this reason gas and vapour filters should be used only to guard against gases and vapours with good warning properties.
When it comes to record-keeping, all reusable respiratory protective equipment (RPE) is subject to the maintenance requirements of the Control of Substances Hazardous to Health regulations (COSHH). Records of monthly maintenance and testing must be kept for at least five years and must be able to be produced on demand for an HSE inspection. Record cards are available from a number of sources including respirator manufacturers.. A monthly check should be made of the face seal, nose cup, straps, valves and gaskets, and visor, with details noted on the record card.
Maintaining good practice in the area of record-keeping, as well as adopting a strict regime of pre and post-use checking, cleaning, maintenance and storage, will help to ensure that employees remain safe and that legal requirements are satisfied.
Aicha Kabil works for the Occupational Health & Environmental Safety Division, 3M