This conversation started with a phone call in late May 2016:
In sum, a business was trying to determine the information necessary in order to classify a substance as a Class 8 Corrosive for transportation in commerce. He had been told that the classification is based on the pH of the substance. I told him that I was almost certain that pH was not a factor in this classification but instead was based on the corrosion rate of the substance on human skin or on steel or aluminum. Not having a copy of the Hazardous Material Regulations with me at the time I took the call I couldn’t cite the regulation my answer was based on so I told him I would follow-up with an email.
And so I did. In an email of May 31, 2016:
My first answer was correct that the USDOT definition of a Class 8 Corrosive Material (liquid or solid) at 49 CFR 173.136 is not based on and does not refer to the pH. Whether a material is a Class 8 is based on two criteria:
- If it causes full thickness destruction of human skin at the site of contact within a specified period of time (see 49 CFR 173.137).
- If it has a severe corrosion rate on steel or aluminum (see 49 CFR 173.137).
He was pleased and had a question I couldn’t answer:
I accepted the compliment but deflected the question: