From what I understand, todays products provide a chemical bond so prep is limited to a thorough cleaning.

Get those at HD, Some for big splash goggles and heavy duty chemical gloves.

All those years the tenants could have been breathing and absorbing the chemicals still in the walls.

Market yourself as being different and unique, and develop a business plan to clean your clients homes and businesses using only products that are chemical free and environmentally safe. 2.

I asked about treated lumber, the fellow said not a good idea, in case someone skins a knee on it, stubs a toe, etc. because of the chemicals used.

I'm chemically sensitive, and belong to MCS fora.

Try Chemical Bank in Cincy, I've had some investors that have had success with them.Let me know if I can assist you in any way!

Radon is a chemical element with symbol Rn and atomic number 86.

We had tried over weeks that we were working upstairs to pour all kinds of chemicals on them to eliminate the smells. 

Existing mold that is isolated (that's the key word here) can easily be killed with chemicals (don't use bleach, get a specialized mold killer, sold everywhere) or ozone.