Release: Arsenic trioxide.

Primary injury: Fish closures.

Arsenic trioxide (As2O3) is a white, odorless, tasteless powder, which is only slightly soluble in water. It is classified as a hazardous material under the Comprehensive Environmental Response, Compensation, and Liability Act, and is a known carcinogen, poisonous by ingestion and dust inhalation, and possibly by skin absorption. It is corrosive to the eyes, skin and mucous membranes. It is also harmful to aquatic life in very low concentrations.

Samples of water, clam tissue, and sediment were collected by the National Oceanic and Atmospheric Administration (NOAA) in and around the spill site for testing. The water and sediment levels for arsenic were found to contain only background (naturally occurring) levels. The Food and Drug Administration found that the arsenic levels in the shellfish tissues were within normal concentrations.