Assessing spill risks and impact from Hazardous and Noxious Substances (HNS): Are standard toxicity data enough?

ABSTRACT 2017-262 Over recent decades there has been an increase in the shipping of chemicals at sea with a subsequent increase in the risk of incidents involving hazardous and noxious substances (HNS). Typically, during HNS spills and during scenario planning the impact upon marine organisms is estimated using spill model predictions of time-weighted average (TWA) or peak concentration compared to a predicted no effect concentration (PNEC) derived from laboratory based constant exposure toxicity studies. This paper evaluates two marine transported chemicals, aniline and benzalkonium chloride, and compares their toxicity during standard (constant) and brief (spill-profiled) exposures. Toxicity was evaluated for the copepod Tisbe battagliai, the red algae Ceramium tenuicorne and the brown algae Fucus vesiculosus. Benzalkonium chloride (BAC) and aniline exhibited toxicity in similar concentration range with EC50s typically 1–2 mg l−1 range during constant exposures. When brief or spill-profiled exposures we...