The Associated Press

CORBIN, Ky. - The state Labor Cabinet has found seven "serious" health and safety violations at a factory where an explosion in February killed seven workers and injured 30 others.

The cabinet announced the violations in two citations Friday against CTA Acoustics Inc. It proposed a $7,000 fine for each violation - the maximum allowed under state law.

The citations against CTA included inadequate ventilation, that the company failed to clean a buildup of combustible dust, and that temperature controls on a gas-fired oven weren't working, so workers left oven doors open to avoid overheating.

Investigators from the U.S. Chemical Safety and Hazard Investigation Board said the blast was caused by a buildup of dust that was ignited by flames that escaped from an open oven door.

The "serious" designation on the violations is less severe than "willful," which carries a fine of up to $70,000 on each violation.

Kembra Taylor, attorney for the cabinet, and spokesman Eddie Jacobs said investigators did not find sufficient evidence of a "willful" violation by CTA.

"We have never been shy about issuing a 'willful' if we think we have the evidence," Taylor said.

CTA could contest the citations or ask for a reduction in the fines. Jim Allen, a Lexington lawyer representing the company, said CTA will review the citations and decide how to respond.

CTA makes acoustic and thermal insulation, primarily for use in cars and trucks. The company combines fiberglass and resin and passes the material through natural-gas ovens to bind it into pelts, then molds them into shape.

The blast at CTA ranks as the worst workplace accident in Kentucky since 1989, when 10 coal miners died in a Western Kentucky explosion.