Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

The amount of benzene, lead oxide, acetone, and hydrochloric acid produced will depend on the temperature of the tip, the amount of rosin in the solder, the amount of solder, the air currents, and how close the person is to the work. So it's impossible to know how large a dose is received, and OSHA seems to fall in line with ACGIH and state "as low a dose as possible" which means good ventillation or respirators to block organics, acids, and metals. Lead, cadmium, and mercury are not the only unhealthy metals, just the ones we've used a lot of in the past that turned out to be bad. Rarer metals have risks that are not well known. Antinomy, tin, tellurium, vanadium, and nickel (as examples) are not safe, and almost any metal when heated to a high temp in the presence of rosin might be bad (tin organics can be really nasty and it melts at a lower temp than lead, so I would not assume the lead in rosin core solder is the most dangerous constituent and I would not trust any government agency to know otherwise (I was an air pollution regulator for 12 years)). Toxicity for metal organics is bad and generally unknown. The link you gave at the bottom is interesting in its comments on asthma. I exposed myself to a lot of high temp rosin core soldering in an unventillated room because I had never heard there was a problem with home soldering. Now I can't breath it at all without having a strong irritation in my throat, and when I visit Lima I start gagging from I assume the sulfur dioxide that produces acid when it hits water in the throat and lungs, so I have to take a yellow cartridge respirator. I think it might be the hydrochloric acid that does this if not the benzene, but my bigger risk might not be related to this irritation but a higher risk of lung cancer from other chemicals which is the largest cause of non-smokers cancer deaths from occupational exposure (perhaps 15,000 in U.S. per year....0.5% of all deaths) so my risk might now be 5% chance it gets me. If I can do 20 things to prevent that kind of risk, I'll live forever ;) BTW, 10 years of holding a cell phone next to the head an hour a day causes 3 times more brain/nerve cancer in adults, 5 times more in children. Studies showing no effect were lower doses not reaching statistical significance, so the public wrongly assumes (as usual) the studies are in contradiction. It's like 5 years of smoking. Congress knows it from hearings (see youtube), but there is no concern from the public to force them into action and of course you know where the lobbies stand.