People who work in industrial hygiene try NOT to admit fault. There are reasons;  legal implications, credibility, and of course, pride. Since this blog is about being transparent, I will confess I made a huge mistake. My mistake wasn’t disastrous, but it could have been.
Background:
Employees were using a hudson sprayer (pump style) to apply a liquid waterproofing material. Air monitoring was performed and found to be 50% of the OELs. However, given the environmental conditions, and different areas they would need to access, I recommended they wear 1/2 face respirators. The hazard was isopropyl alcohol and a 1/2 face respirator with organic vapor cartridges was sufficient, with goggles & protective clothing.
However. It wasn’t isopropyl alcohol….it was methyl alcohol (methanol). And, there is a HUGE difference. Organic vapor cartridges (filters) provide NO protection to methanol. I should have recommended supplied air respirators.
I feel terrible, and I apologized.
“Success does not consist in never making mistakes but in never making the same one a second time” – George Bernard Shaw