Anyone wearing a respirator must be trained and authorized by the company in several different areas such as how to put on and take off the respirator. We call that Donning & Doffing. The process is simple, but it does require some basic knowledge which we'll now review. You are being asked to select the respirator that provides the most acceptable fit. A mirror must be provided to assist you an evaluating the fit and positioning of the respirator. Each respirator represents a different size and shape. And if fitted and used properly will provide adequate protection. Hold each face piece up to the face and eliminate those that do not give you an acceptable fit. Put the most comfortable mask on your face and wear it for at least five minutes. If you're not experienced wearing a respirator put it on and take it off several times to become familiar with the process. Be sure to adjust the straps each time the respirator is donned. While wearing the respirator check the comfort of the mask, how it fits your face, nose, and proper seal between the mask and your face and cheeks. Make sure your chin fits the respirator. Check the strap tension to make sure its not too loose or too tight. Some respirators have a tendency to slip. So check the fit in the mirror and through testing of the fit. Move your mouth as if talking to make sure you don't break the seal or fit. Before conducting the negative and positive pressure checks set the mask on your face and move your head from side to side and up and down to ensure a stable fit. Make sure there is room for eye protection and good vision. If you wear glasses the glasses cannot extend through the seal of the mask.

Conduct seal checks. If you have any facial hair or sideburns that would prevent a proper seal you cannot wear or select the respirator. While selecting or wearing a respirator, and you have difficulty in breathing, you must stop and be provided a medical evaluation before being allowed to use respiratory protection. To conduct a “positive pressure seal check” close off the exhalation valve, and exhale gently into the face piece. The face fit is considered satisfactory if a slight positive pressure can be built up inside the face piece without any evidence of outward leakage of air at the seal. The negative pressure test is conducted by closing off the inlet opening of the canister or cartridges by covering with the palm of the hands, or by replacing the filter seals. To remove the respirator you should loosen the straps, and while pulling on the straps, allow the mask to gently release from the face seal. Upon removing the mask it should be cleaned, disinfected, and stored according to the manufacturer's recommendations.

Let's now take a look at some of the different types of respirators so you'll have a better understanding of proper selection for the hazard to which you may be exposed. Okay, let's begin with permissible exposure limit. PELs are exposure limits for each different chemical. Established by OSHA, PELs may be expressed as a Time Weighted Average, or TWA, or as a ceiling exposure limit. TLV, or threshold limit values, are used by industrial hygienists to express the airborne concentrate of a material to which nearly all workers can be exposed day after day without adverse effects. Each chemical, or airborne concentration has different TLVs. Oxygen deficiency simply means there isn't enough oxygen in the air to support life. IDLH is Immediately Dangerous to Life and Health. All oxygen deficient atmospheres must be considered IDLH. The word particulate means a particle of solid or liquid matter. Matter is divided into three states: solids, liquids, and gases. Solids are either finely divided dust particles such as from grinding operations, or as still more finely divided metal fume particles as generated when smoldering hot metals vaporize.