Following closure of a substantial part of the BHP Steelworks at Newcastle, New South Wales, the smell of ammonia from occasional accidental emissions bad become more apparent to people living and working around the plant. Incitec, therefore, conducted a review of all potential emission points where accidental releases of ammonia could occur A detailed study was then carried out to quantify the frequency of each emission, the amount released, and the downwind concentration in populated areas. A risk grid was devised to help decision-making for the various releases, and, for those emissions that did not meet the required frequency-consequence standards, improvements were devised to reduce either the frequency or the consequences, or both. For the ammonia plant this has led to several significant modifications. This paper describes the study and some of the resulting environmental improvements implemented on the ammonia plant, the ammonia storage area, and downstream nitrates plants.