The smoke was carried out of the plant and near some area homes. Seven houses were evacuated until the air cleared.
Beryllium is a strong, lightweight metal used in the defense, automotive, and electronic industries.
It is used to make, among other things, nuclear bombs. Beryllium dust can cause chronic and sometimes fatal lung problems for those who inhale it. The amount of beryllium in the air when it was tested Thursday morning was 0.65 micrograms per cubic meter. That is within the safety standard of 2 micrograms per cubic meter set for indoors by the Occupational Safety and Health Administration. For outdoors, the U.S. Environmental Protection Agency has an emission limit of an amount that over a 30-day period would average 0.01 micrograms per cubic meter.