You shouldn't have anything to worry about unless your making your own chemical mixture to clean roofs. If your mixing up your own chemicals for it and you don't have an msds or insurance for manufacturing chemicals you could have one hell of a mess with this client.
If your buying your chems, just turn them over to the manufacturer and let them deal with it.
Henry, very good answer!
We cleaned many roofs in the past and this summer decided to stop. There was too much liability, first the added insurance cost to cover me or someone else on a roof made my head spin, second mixing chems, leaking pumps, leaking bulkheads thru the years are very frustrating as well.
Yes there is good money to be made but I started thinking the exact thing you just stated, unless I mix on site I am taking a huge risk, if we had an accident or a spill it would be aweful, could you see me trying to show the DOT an MSDS for some surfactant like Borax plus TSP and 12.5% Sodium Hypochlorite? Oh my oh my, I bet the guys head would pop off when he found out I had all that mixed together and had no license to manufacture.
That being said I sort of like AC's new thing with the powered chems, I watched the video and it seems a safe alternative, he provides you with the formula to mix the chems and they are transported dry and not mixed. May be worth looking into. Plus he provides the MSDS and the instructions ect so I am assuming he has looked into the legal end of it as well. I will have to dig further on that one.
In closing, not to poke at Mark but Mark you have a serious issue on your hands, I spend a lot of time on our yard and my wife would throw a fit if that had happened here, another thing, I would look at the neighbors homes, if they still look good around there house you may be replacing more than a tree before its over. If the tree is found to be caused by you I am sure a judge will naturally assume that the rest was too.