Patent ID: 6921553

Claim:
A method of treating a chrysotile-asbestos containing porous building material (ACM) installed on a substrate in a building, comprising: (a) providing a composition derived from admixing (i) water, (ii) at least about 30% by weight of an acid component comprising an inorganic acid, an inorganic acidic salt or mixtures thereof, (iii) from about 0.1 to about 4% by weight of a source of fluoride ions, and (iv) a stable foam generating amount of a foaming agent system comprising at least one non-ionic polyalkyglycoside represented by the formula: wherein R represents a C 8 to C 16 alkyl group and x represents an integer of from 1 to 10, alone or further with a second non-ionic agent; (b) foaming the composition from step (a); (c) applying the resulting foamed composition to the ACM chrysotile asbestos-containing building material; (d) permitting the foamed composition to remain on and penetrate the building material and contact the chrysotile asbestos contained therein; (e) allowing said composition to remain in contact with the chrysotile asbestos for a sufficient period of time to reduce the amount of chrysotile asbestos contained in said building material to less than 1% by weight of the resultant material; and (f) permitting said resultant material to remain on the substrate of the building.