Ammonia was accidentally released at a Grimmway Farms plant near Arvin Monday, forcing the evacuation of employees at the company's facility on Malaga Drive.
A county official said no one was sickened. But a Facebook post about the incident attracted comments by two women who reported workers were sent home feeling ill.
A spokeswoman for Kern County's public health department said by email Tuesday afternoon the release occurred at 5:45 a.m., prompting a shutdown of operations. She added that a faulty pressure-release valve was determined to be the cause and that no one was injured or sickened.
Grimmway, one of the country's top growers and processors of carrots, said by email a small amount of ammonia was released at the plant.
"The leak was limited to one building within the facility," the company stated. "We caught it and the leak was controlled quickly. In line with our company procedures, all employees in the area were evacuated out of an abundance of caution. No injuries were identified, and all appropriate regulatory agencies have been notified."
California's Department of Industrial Relations, the agency responsible for enforcing workplace safety rules, said by email Tuesday afternoon it could not confirm the incident.
One of the Facebook commenters, Dominga Quintanar, asserted workers at the plant were told to go outside after the release and then were sent home at about 9:45 a.m. She wrote that her husband came home with a headache.
Another commenter, Teresa Morales, wrote on Facebook that an alarm was sounding when her husband arrived at the plant at 6 a.m. She added that people were sent home "because of the exposure and workers feeling sick."
Exposure to low concentrations of ammonia causes coughing and irritation. Higher concentrations can burn the nose and throat, potentially leading to respiratory distress or failure.