ON Marine Services Company LLC is a Delaware-based entity and a wholly owned subsidiary of Oglebay Norton Company, which is currently owned by Carmeuse Lime, Inc. Historically, the company operated through its Ferro Division, which manufactured and sold refractory products, specifically asbestos-containing "hot top" insulation for steelmaking ingot molds, until production ceased in 1978. The company maintained active business operations until 2010 and currently manages the resolution of legacy asbestos-related personal injury claims.