On a slightly different subject, I cleaned a customer's oven a while back and advised the customer to turn the grill/oven on to let the chemical's burn off before placing food in it.
A few hours later he rang to say his son's mouth had swollen having eaten cheese on toast from the top grill. He hadn't done as I asked him to do.
His wife was on the other phone to the NHS helpline who'd asked for the COSHH information. I was fortunate to have had the fore-thought to download COSHH sheet for every new product I buy, so I was able to give them the information immediately.
The outcome was that their child's mouth was fine after half an hour, and now "I" switch the oven/s on for the customer. The child's father actually apologised to me for not doing as I advised, but I still felt really responsible for not doing it myself... You live and you learn.....