Experience of tumors in a British plant handling 3 3' dichlorobenzidine.

Dichlorobenzidine has been handled at a plant in Britain over the past thirty years. No case of cancer of the bladder has been found in the exposed population. The population of two hundred and 25 is not large enough to prove DCB will not cause tumors, but a negative incidence, taken with American experience and European figures, (unpublished) suggest that the measures advocated by Scott and Williams and at present adopted provide a satisfactory code of practice.