The laboratory environment requires control through proper humidity and air ventilation and carrying out all hazardous operations in fume hoods. At times, however, you may have to work on highly toxic, poisonous, carcinogenic materials or harmful bacteria and viruses. In such situations make use of laboratory facemasks to prevent breathing intake of such potentially dangerous materials through unprotected exposure. In such situations face respirators come to your rescue. It is therefore necessary to have knowledge of the various types of protective masks available and how their effectiveness can be retained for longer time periods.
Types of laboratory face mask respirators
Respiration facemasks help you breathe filtered air in contaminated environments The mask should be certified by National Institute of Occupational Safety and Health (NIOSH) and in compliance with the respiratory protection standard 29 CFR 1910.134.
Respirators can be broadly classified into two categories, namely, those for protection in an environment not having high a risk but the risk has potential of buildup over prolonged or repeated exposure. The other class are meant for emergency or rescue operations in highly hazardous environments. In such cases when the airborne contaminant poses additional dangers such as skin absorption, irritation, etc, then full body protection becomes necessary.
The choice of face protection masks depends on factors such as type of contaminant, its hazard potential, concentration, etc.
Cartridge respirators offer protection from specific vapours and gases. The concentration range over which they are to be used is specified on each piece and its use should not be exceed beyond prescribed limits. In case you are able to smell the vapour or have difficulty in breathing leave the contamination area immediately.
Powered air respirators
In addition to the cartridge provision is made for supply of fresh air through a battery operated blower. A positive air pressure facilitates outward flow of air from the mask thereby restraining entry of contaminated gas inside. Care must be taken to ensure that the battery remains charged. Such respirators are useful in oxygen deficient environments.
Dust respirators serve to keep particulate matter out. These are strictly speaking not respirators and are not covered under NIOSH compliance. They are basically fiber based filters and are generally disposable. Keep in mind that dust respirators offers no protection from chemical vapours and gases so have limited laboratory applications.
Care of respirators
- Single use respirators should be disposed off after use
- Inspect respirators for cracks, tears or holes before use
- Replace cartridges periodically depending on use and level of contamination in affected areas
- Clean after each use taking care that the cleaning agent does not damage the respirators
- Clean the air filters in powered air respirators and ensure that the battery is charged before use
- Do not use respirators for unspecified use in different environments
- Do not share respirators with others
- Remove cartridges after use and store in sealed containers to prevent further absorption of contaminant over the storage period.
Proper care and attention to detail will provide you the required protection in contaminated areas besides extending their useful life span.