12oz flame retardant denim fabric is a heavy-weight denim material treated with durable flame retardant finishes. The unit oz (ounce) refers to fabric weight per square yard; 12oz stands for medium-heavy grade denim. It combines the classic texture, sturdiness of traditional denim with flame resistant performance, mainly used for manufacturing protective workwear, heavy-duty jackets, coveralls and work trousers for industrial fire-hazard environments.