Painting with Harderners

1- Iso's are very toxic and small amounts, even single exposures can sensitize you (make you more susceptable in the future) or even cause acute respiratory problems. So, even a small exposure is an issue.

2- Iso's can break through charcoal filters without you knowing it. They have very little odor. There are no indicators when you have saturated the filter.

3- Charcoal filter masks are negative pressure (when you inhale) devices. How well they seal is an important issue. Even small leaks can let the dreaded iso's in. Supplied air positive pressure devices don't have this issue...

I think (and hope) that you are convinced that supplied air is the way to go, but I wanted to provide the reason why filters are no longer permitted in the industry... because they were used (tragically unsuccessfully) for some time... J2

Here a few quotes from the web...

“Respirators used to be replaced only when “break-through” was detected. Break-through is when the user can taste or smell chemicals while the respirator is being used. This detection method is not safe because it is impossible to know the exact point at which any chemical actually breaks through. Depending on each person’s level of sensory capabilities and fatigue, chemicals may be sensed at different times by different people. Also, some chemicals do not have a significant taste or smell, such as isocyanates.”

“Di-isocyanates have low odor threshold and are not easily detected by smell. A dangerous level of di-isocyanates can break through a charcoal filter cartridge before the user is able to smell it. Painters using such paints must use an air-supplied respirator.”

Well, it sure is easy to recommend personal safety equipment to others where your own health is not at risk and there are no ramifications of a bum recommendation. Sort of like recommending Russian Roulette to someone. After all, the odds are probably in your favor. If you've read any of my posts on the matter in this forum, you'll know that my answer is no. Period. No fresh air respirator, no hardeners. Inside or outside. Brush or spray. A charcoal mask will not cut it. However, since it's your risk, it's also your decision. There are lots of reference reading materials previously posted in this forum from recognized authorities on painting and health safety. I strongly recommend you read over many of them before making your decision. At a bare minimun, you should read the MSDS (manufacturer's safety data sheet) for the hardener you are considering using. It will spell out the recommended safety equipment for you to consider, including breathing specifics.

PS: Your paint distributor may not know what a MSDS is. You should ask him for a copy of the one that applies to the specific hardener he is recommending a charcoal mask is OK to use with. If he doesn't have it, find another distributor. Actually, knowing the manufacturer and product details, the MSDS is usually available from the manufacturer's website. However, you should query your supplier to see how much he really knows about the products he's trying to sell you. You may find he doesn't know as much as he thinks he does.

Rod