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Old 08-25-08, 12:44 AM
John C. Ratliff
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Originally Posted by Six jours View Post
So you are saying that people should decide for themselves how much protection is appropriate, based upon their individual situations? Welcome to the dark side.
You always base the PPE choices upon the hazard. For instance, for some airborne contaminants, a half-face respirator is appropriate, with a protection factor of 10 times the Permissible Exposure Limit (PEL) or Threshold Limit Value (TLV), depending upon the standard you wish to use.

Toluene has a TLV of 20 parts per million. A half-face respiator will protect up to 10 times that amount, or 200 ppm. But if the amount is greater, than a better respirator is needed, say a full-face respirator (protection factor, 50 times the PEL or TLV). But if you are a member of a Emergency Response Team (ERT) responding to a spill where the concentration is unknown, you will want a pressure-demand self-contained breathing apparatus with a full-face mask, which has a protection factor of 1000 times the TLV, or in this case, 20,000 ppm. But at 20,000 ppm, you are getting into another problem with the lower explosive limit, so you can only take this analogy so far.

Helmets don't come with assigned protection factors (that may be a nice idea though). So you need to make a choice about what type of protection is warranted for a particular activity. I went to the NBC Olypmic coverage, and viewed some of the BMX spills, and they do need the entire facial protection. I also watched some of the mountain biking spills, and they had some significant hits on the ground and to trees, but not on the front of the face like I saw in BMX, and not at the speeds that the BMX riders were going, or the heights of the BMX riders.

Just because there are choices to be made with what PPE to use for a particular situation doesn't mean that a choice of no PPE is warranted, based upon the risk. There is more risk of spills off a bike than for a pedestrian, although when walking in winter on ice, that helmet might not be such a bad idea for a pedestrian. One notable physician, Dr. Atkins, recently passed away from a head injury while slipping on ice:

Had Dr. Atkins been wearing a helmet for that walk, or perhaps shoe chains, we would still be hearing more about the Atkins diet.


Last edited by John C. Ratliff; 08-25-08 at 12:49 AM. Reason: add link to respiratory protection factors
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