How do I put on the Dorma 99 respirator and check for an effective seal?

Dorma 99 donning and seal check instructions

To put on the Dorma 99 respirator, cup the respirator in your hand, with the nosepiece at your fingertips, allowing the head strap to hang freely below your hand (Fig 1). With the nosepiece up, place the respirator over your nose and mouth. Make sure that the respirator rests on the nose. The bottom part of the respirator should be placed between the lower lip and under the chin, depending on the length of the user’s face. Pull the top strap over your head, resting it high at the top of the back of your head (Fig 2). Then adjust the strap length through the eyelets so that the respirator comfortably covers both your mouth and nose (Fig 3). Fasten the clips behind your neck (Fig 4) and pull the loose strap ends to tighten to an appropriate tension (Fig 5).

A seal check must be performed each time the respirator is put on. Use one or both hands to completely cover the respirator filter, and exhale (Fig 6). The respirator should budge slightly. If air leaks at the respirator edges, reposition the respirator on face and/or readjust tension of head strap to eliminate the leakage (Fig 7). Once the seal check is successful, the respirator is ready for use (Fig 8).

Fig 1 Fig 2 Fig 3 Fig 4
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Fig 5 Fig 6 Fig 7 Fig 8
Donning-fig-5 Donning-fig-7 Donning-fig-6 Donning-fig-8

For further details, read the Donning Instructions