Five more Hanford workers received medical checks for possible exposure to chemical vapors from tank farms Thursday, according to Washington River Protection Solutions.
Four Hanford employees were working between the AW and AP Tank Farms Thursday, when an odor consistent with chemical vapors was smelled.
One of the employees had symptoms, and all four were given medical evaluations.
In addition, a worker who smelled an odor outside the C Tank Farm on Wednesday developed symptoms overnight. The worker reported the symptoms Thursday and received a medical evaluation.
The five workers have been released to return to work.
In all 54 workers have received medical evaluations for possible vapor exposure since early spring.
Although symptoms were not made public, typical symptoms of chemical vapor exposure from waste stored in Hanford’s underground tanks include headaches, coughing, dizziness and shortness of breath.
Last week the tank farm contractor began requiring workers entering Hanford’s single-shell tank farms, which have passive ventilation systems, to wear respirators.
C Tank Farm has single-shell tanks, but the worker was just outside it and not covered by the respirator requirement. The AW and AP Tank Farms have double-shell tanks.