Professional Practice of Environmental Auditing in Nigerian Manufacturing Firms: Standards, Challenges, and Outcomes

This study examines the professional practice of environmental auditing in Nigerian manufacturing firms, assessing the standards applied, challenges encountered, and outcomes achieved by environmental audits conducted at manufacturing facilities across multiple industrial sectors. Environmental auditing is a core tool of professional environmental management, providing independent verification of regulatory compliance and management system performance, but the practice of auditing in Nigeria's manufacturing sector is not systematically characterised in the environmental management literature. A survey was administered to forty environmental audit practitioners who have conducted audits at Nigerian manufacturing facilities, covering their qualifications, audit scope and methodology, client types, reporting practices, and perceptions of audit quality and impact. This was supplemented by structured interviews with fifteen environmental managers at manufacturing firms across Lagos, Kano, Ogun, and Rivers States who have commissioned or hosted environmental audits. Results reveal wide variation in audit scope and quality, driven partly by the absence of a mandatory national standard for environmental audit practice. Second-party audits for ISO 14001 certification are the most methodologically rigorous, while regulatory compliance audits required by NESREA are frequently conducted at low depth due to time and fee pressures. Common audit findings across sectors include wastewater treatment underperformance, inadequate chemical storage management, and incomplete environmental record-keeping. Audit findings are estimated to translate into management action in fewer than 50 percent of cases, driven by inadequate follow-through processes. Recommendations include developing a national environmental audit standard for Nigerian manufacturing and establishing a professional register for environmental auditors. Keywords: environmental auditing, manufacturing, professional practice, compliance, environmental management.