Inflammatory damage to skin by prolonged contact with 1,2-dichlorobenzene and chloropentafluorobenzene

Skin samples from Fischer-344 rats and Hartley guinea pigs exposed dermally to 1,2-dichlorobenzene (DCB) and chloropentafluorobenzene (CPFB) for up to 4 h were examined for chemical-induced damage. Samples were stained with hematoxylin and eosin and scored for polymorphonuclear cell (PMN) margination, dermal inflammation, and epidermal necrosis by light microscopy. Ultrastructural evaluation of samples fixed with 2% glutaraldehyde and postfixed with 1% osmium tetroxide was used to visualize margination of PMNs. Guinea pigs exhibited postexposure inflammatory changes following an exposure of about an hour-and-a-half shorter duration than rats. DCB-induced inflammation and PMN margination occurred following an exposure about a half hour shorter in both species compared to CPFB. In contrast, epidermal necrosis was more severe with CPFB than with DCB. These changes may account for decreases in chemical penetration rates which have been observed in previous studies with DCB and CPFB in rats and guinea pigs.