There are four simple principles of respiratory protection:
- Always select the right respirator for the task e.g. correct filters
- Always ensure a proper face fit. Fit test if necessary.
- Have an active maintenance program to support the devices in use, including cleaning and defect recognition.
Ensure proper storage of equipment. Best kept in an airtight container.
Contaminant
Three main factors need to be considered when selecting a suitable respirator for a particular situation.
These factors are:
- The nature, toxicity, physical form and concentration of the contaminant.
- Always ensure a proper face fit. Fit test if necessary.
- Have an active maintenance program to support the devices in use, including cleaning and defect recognition.
- The adequacy of the warning given by the contaminant, e.g. odour threshold.
- The possibility of the contaminated atmosphere being flammable.
Task
- Whether the device is for regular use or for emergency or rescue purposes.
- The probable length of time during which the wearer will be in the contaminated atmosphere.
- The expected level of activity and mobility required by the wearer.
- Whether the access and location air source is suitable for breathing.
- The need for clear vision and communication.
- The facilities available to maintain the device.
Operator
- The effect of the general environment on the operator.
- The importance of facial fit (the presence of facial hair will adversely affect the fit).
- The expected level of activity and mobility required by the wearer.
- The comfort afforded by the respirator over extended periods of use.
If you have any doubts as to the correct device for a particular situation, you should seek expert advice.
Work Exposure Standards
When selecting a respirator to protect against a workplace contaminant, it is necessary to know:
- The physical and chemical properties of the contaminant,
- The concentration of the contaminant in the workplace environment,
- The Workplace Exposure Standard (WES) for the contaminant,
- The Respirator Protection Factor.
The physical and chemical properties of the contaminant, and its effects on the body, can be ascertained from the most current Material Safety Data Sheet (MSDS) from the supplier of the substance concerned.
Workplace Exposure Standards represent the maximum atmospheric concentration of a contaminant to which most workers can be safely exposed. A full description of these is contained in the OSH publication Workplace Exposure Standards and Biological Exposure Indices for New Zealand (July 2011).
