About 50 firefighters remained at the plant early Friday evening, removing cellulose, which is an ingredient in pet food, from a large bin in the area where the explosion occurred.
Iams Co. employees had become concerned about the bin of cellulose Thursday when they saw smoke coming from a conveyor that was filling the bin and called firefighters then.
Friday morning, employees again noticed faint smoke in the area. They called firefighters to wet down the cellulose with hoses as they emptied the bin.
The explosion happened about 1:45 Friday afternoon when about eight Iams employees and about six firefighters were emptying the bin.
Volunteer firefighter Rick Recker, 38, of the Leipsic area, was flown from the plant to St. Rita