All three samples present a serious hazard from their effect upon the eye and skin. Good care and cleanliness must be exercised, together with the use of special precautions to prevent contamination of the eye and skin, if difficulty in handling is to be avoided. No difficulty should arise from ingestion except for local irritation of the mucous membranes. Absorption of toxic amounts through the skin does not present a problem. These conclusions are based upon range finding toxicological tests and are limited to precautions for industrial handling of the material. Development of specific uses will require consideration of the health problems presented and of the need for further toxicological studies.