The blast ripped through the facility in Garner, Northern Carolina, yesterday at 11.30am local time killing two and injuring at least 40, many of whom needed medical attention after inhaling ammonia.
The 500,000 square metre plant, which processes Slim Jim meat products, employs 900 workers, although only 280 were on site at the time of the explosion.
"No words can express how saddened we are by these events today," said Gary Rodkin, CEO of ConAgra Foods. “We will continue to work with local authorities to identify the cause of this accident.”
The US Chemical Safety Board, which investigates chemical accidents, has sent a team to the site. The board makes safety recommendations to plants, industry organizations, labor groups and regulatory agencies but doesn’t have authority to issue citations or levy fines.