A carbon monoxide leak in a warehouse in the Lehigh Valley sent close to 20 workers to the hospital Sunday in East Allen Twp., Northampton Co.
Fire officials said the potentially deadly gas was coming from an area where forklift batteries are charged in a Trader Joe's warehouse.
First responders swarmed the warehouse on Silver Crest Road just after 7 a.m,. Sunday.
Emergency workers discovered the carbon monoxide leak while responding to a fire alarm.
"Once we entered the warehouse, that started alarming for carbon monoxide," said East Allen Township Fire Department Assistant Fire Chief Ray Anthony.
Levels for the colorless and odorless gas were high through the entire 800,000-square-foot building.
The readings reached 55 parts per million in some areas. Normally those levels are zero. All 197 employees were evacuated outside for safety.
"We determined the source of that carbon monoxide was coming from an area where they charged the batteries for their forklifts," Anthony said.
Once the workers were outside, Anthony says it was clear they weren't all OK.
"They walked up to ambulance crew who were there and had symptoms of some nausea, dizziness, lightheadedness and stuff like that."
In all, 21 people were evaluated by EMS on scene, and 18 others were taken to nearby hospitals. Five forklifts were removed from the warehouse, and the building was ventilated.
"Severe cases of carbon monoxide poisoning can be fatal and can also cause some significant disability," said St. Luke's Hospital attending emergency physician Dr. Mark Reiter.
He said detection of CO is key, but most exposures to carbon monoxide are relatively minor.
"If you continue to stay in an environment that has really high carbon monoxide levels, then you can get sicker and sicker."
Long exposures can be fatal. The trouble is symptoms are relatively non-specific.
"Carbon monoxide usually presents with things like headaches and fatigue and sometimes trouble breathing and nausea," Reiter said.
He said the best thing you can do to protect yourself is have a CO detector. It's something fire officials said was missing from the Trader Joe's warehouse, and some workers think the leak started days ago.
"Apparently these folks were complaining of being ill since Friday," Anthony said.
Representatives from OSHA and the Department of Agriculture inspected the building.
Under OSHA standards the permissible exposure limit for carbon monoxide is 50 parts per million for eight hours.