EXPERIENCE FROM A LONG-TERM CARCINOGENICITY STUDY WITH INTRAPERITONEAL INJECTION OF BIOSOLUBLE SYNTHETIC MINERAL FIBERS

The carcinogenic potential in the intraperitoneal cavity of three newly developed biosoluble insulation glass wool fibers (M, P, and V) and one newly developed biosoluble insulation stone wool fiber (O) was investigated and compared to that of a previously developed soluble glass fiber (B). The in vitro dissolution coefficient of the three glass wool fibers ranged from 450 to 1037 ng/cm 2 × h and was 523 ng/cm 2 × h for the stone wool fiber. The in vitro dissolution coefficient of the B fiber was 580 ng/cm 2 × h. Groups of female Wistar rats (strain Crl: Wi BR) were exposed by repeated injections to doses of 0.5, 2, and 5 × 10 9 WHO fibers, which corresponds to between 41 mg to 724 mg fiber injected. In addition, 2 groups of crocidolite were used as positive controls at doses of 0.1 × 10 9 and 1 × 10 9 WHO fibers (0.5 and 5 mg). The in vitro dissolution coefficient of crocidolite is estimated to be ~1 ng/cm 2 × h. The protocol of the study and the size distribution of the test samples conformed to the Eur...