Re-creation of historical chrysotile-containing joint compounds.
Chrysotile-containing joint compound was commonly used in construction of residential and commercial buildings through the mid 1970s; however, these products have not been manufactured in the United States for more than 30 years. Little is known about actual human exposures to chrysotile fibers that may have resulted from use of chrysotile-containing joint compounds, because few exposure and no health-effects studies have been conducted specifically with these products. Because limited amounts of historical joint compounds are available (and the stability or representativeness of aged products is suspect), it is currently impossible to conduct meaningful studies to better understand the nature and magnitude of potential exposures to chrysotile that may have been associated with historical use of these products. Therefore, to support specific exposure and toxicology research activities, two types of chrysotile-containing joint compounds were produced according to original formulations from the late 1960s. To the extent possible, ingredients were the same as those used originally, with many obtained from the original suppliers. The chrysotile used historically in these products was primarily Grade 7RF9 from the Philip Carey mine. Because this mine is closed, a suitable alternate was identified by comparing the sizes and mineral composition of asbestos structures in a sample of what has been represented to be historical joint compound (all of which were chrysotile) to those in samples of three currently commercially available Grade 7 chrysotile products. The re-created materials generally conformed to original product specifications (e.g. viscosity, workability, crack resistance), indicating that these materials are sufficiently representative of the original products to support research activities.
Brorby
G P
GP
Exponent, Inc., Oakland, California 94607, USA. gbrorby@exponent.com
Sheehan
P J
PJ
Berman
D W
DW
Greene
J F
JF
Holm
S E
SE
D017632:Asbestos, Serpentine / Q000009:adverse effects* / Q000737:chemistry / Q000266:history; D003252:Construction Materials / Q000009:adverse effects* / Q000032:analysis / Q000266:history; D049673:History, 20th Century; D006801:Humans; D019570:Inhalation Exposure; D008422:Materials Testing; D019016:Mineral Fibers; D016273:Occupational Exposure; D010316:Particle Size; D018570:Risk Assessment; D014783:Viscosity
D017632:Asbestos, Serpentine; D019016:Mineral Fibers
Am Ind Hyg Assoc J. 1979 May;40(5):402-7
463751
Risk Anal. 1995 Apr;15(2):181-95
7597255
Am Ind Hyg Assoc J. 1980 Apr;41(4):264-9
7395743
Ann Occup Hyg. 1990 Apr;34(2):159-75
2169219
Science. 1975 Aug 15;189(4202):551-3
1145211
Crit Rev Toxicol. 2008;38 Suppl 1:49-73
18686078
Inhal Toxicol. 2008 Sep;20(11):1009-28
18788018