SAN FRANCISCO—On August 27, workers at Pier 96, the city's recycling and sorting facility, operated by Recology, were sickened by a "white powder" that burst open at the recycling facility.

San Francisco Fire Department spokeswoman Mindy Talmadge states that a cardboard box containing ammonium phosphate, a fertilizer, burst open on a conveyer belt.

The incident  prompted an evacuation of the factory well before 6:40 a.m. The plant was evacuated for three hours while emergency personnel spent all morning inspecting the site to make sure it was safe for the workers to resume their duties inside the plant.

Ammonium phosphateis is classified as "non-toxic," but if you have contact with it, particularly your  eyes, it may cause discomfort. If for some reason you happen to swallow the ammonium phosphate, the symptoms include diarrhea, nausea, abdominal cramps, or methemoglobinemia, which is a disorder characterized by the presence of a higher than normal level of methemoglobin (metHb) in the blood that results in almost no oxygen delivery to the tissues.

Spokesman for Recology Robert Reed said 55 employees were working within the 200,000-square-foot building at the time of the occurrence. Twenty employees let emergency personnel know they felt some kind  of eye irritation, and a dozen others had their eyes flushed out.