We had a similar request some time back, and I thought about it for a while, and responded to the customer in this way....
In order to give you a response that would be meaningful, we would need to get similar responses from our vendors. When asked they politely said that they would be happy to do the testing for us, but would have to add the cost of it on to their bills, and we would have to add that to the cost of we were charging our customer, and did they want us to proceed?
They never got back to us...:-)
Rudy Sedlak
RD Chemical Company