9 Concepts of Industrial Hygiene. Exposure / Exposure Control / PPE / Masks. Why Masks Do Not and Can Not Work. What Works & Damage to Adults/Children. Presentation, Stephen E. Petty, P.E., C.I.H., C.S.P. EES Group, Inc. (granitegrok.com) posted 2 years ago by Geomaniac 2 years ago by Geomaniac +9 / -0 11 comments share 11 comments share save hide report block hide replies
You seem to be wandering off topic.