Occupational Exposure Assessment and Control of Volatile Organic Compounds in Paint Manufacturing Plants in Kaduna State

Paint manufacturing operations in Kaduna State, North West Nigeria, involve the use of toluene, xylene, acetone, and methyl ethyl ketone, which are volatile organic compounds associated with chronic neurological and hepatic disorders at occupational exposure levels. This study assesses worker exposure to selected volatile organic compounds in four paint manufacturing plants in Kaduna Industrial Area, compares measured exposure levels against the ACGIH threshold limit values, and evaluates the effectiveness of existing engineering control measures. Personal air sampling using activated charcoal tubes was conducted over three consecutive 8-hour work shifts per facility, and samples were desorbed with carbon disulphide and analysed by gas chromatography. Airborne concentrations of xylene (geometric mean: 188 mg/m3) and toluene (geometric mean: 142 mg/m3) at thinning and filling stations exceeded the ACGIH 8-hour threshold limit values at two facilities. Engineering controls in place included general dilution ventilation and partially enclosed mixing tanks, but local exhaust ventilation was absent at filling stations in three plants. Dermal absorption contribution to total exposure was estimated to be substantial for toluene based on biological monitoring data from urine hippuric acid measurements. The study identifies thinning, filling, and can-sealing operations as critical exposure hotspots and recommends a hierarchy of controls prioritising local exhaust ventilation installation, process enclosure, and enhanced personal protective equipment compliance. Keywords: volatile organic compounds, paint manufacturing, occupational exposure, Kaduna State, engineering controls