Document vb8REJ0NKYg4kM2VZZjN9zj6

PTB-48-7A February 15, 1979 Replaces PTB-48-7 ASBESTOS IDENTIFICATION IN OLD CALSIL INSULATION* Because of the health hazards involved in working with asbestos, it is essential that old asbestos-containing calsil be properly identified to avoid accidental worker exposure during maintenance or removal procedures. Prior to the early seventies, all calcium silicate insulation, and several other types as well, contained asbestos as the reinforcing fiber. Most of the asbestos used was chrysotile, but other types such as crocidolite and amosite were also used. All are hazardous to health. Since the early seventies, all manufacturers have switched to either glass c or organic fibers for reinforcement. Because of the refractory nature of asbestos fibers, they are not destroyed by the flame from a propane (Bernzomatic) torch. Rather, they glow as little incandescent rods in the propane flame. Since the newer fibers -- glass, rayon, polyester, cotton, etc. -- are destroyed by the propane flame, this provides an easy means of positive identification for asbestos. The simple procedure is as follows. 1. Break a small piece of insulation off a section of calsil. 2. Heat the broken surface with the flame from a propane torch. 3. Observe. Figure 1'shows asbestos-containing material. The material in Figure 2 does not contain asbestos. 4. With some experience, a good worker can break off a chunk of insula tion and tell by eye whether or not asbestos is present. A small magnifier makes the process even simpler to carry out. L *NOTE: Since December, 1978, the Pabco Division started to mark all of their Super Caltemp production with an identifying green stripe that shows it is asbestos free. The tecnnu:.* cioto niiown .ire considered tv os to bo .iccwraf md reliool*. no.vever, /io warranties oxnress tyr . ,.<0 r^veo or intunncu mo any utn w.i-r.mnes jre eorossiy nscl>iirn<Ml." PABCO INSULATION DIVISION Louisiana-Pacific Corporation 1110 16 Road Fruits, Colorado 81521 UCTC0S272