Acute toxicity of para-nonylphenol to saltwater animals

para-Nonylphenol (PNP), a mixture of alkylphenols used in producing nonioni c surfactants, is distributed widely in surface waters and aquatic sediment s, where it can affect saltwater species. This article describes a database for acute toxicity of PNP derived for calculating a national saltwater qua lity criterion. Using a flow-through exposure system with measured concentr ations, we tested early life stages of four species of saltwater invertebra tes and two species of fish. Static 96-h tests were also conducted on zoeal Homarus americanus, embryo-larval Mulinia lateralis, and larval Pleuronect es americanus. The number of organisms surviving the flow-through test was measured at 2, 4, 8, and 12 h and daily through day 7. Mortality for most s pecies plateaued by 96 h. The ranked sensitivities (96-h 50% lethal concent rations, measured in micrograms per liter) for the species tested were 17 f or Pleuronectes americanus, 37.9 (48-h 50% effective concentration) for Mul inia, lateralis, 59.4 for Paleomonetes vulgaris, 60.6 for Americamysis bahi a (formerly Mysidopsis bahia), 61.6 for Leptocheirus plumulosos, 70 for Men idia beryllina, 71 for Homarus americanus, 142 for Cyprinodon variegatus, a nd >195 for Dyspanopius sayii. Values for the seven most sensitive of these species ranged over a factor of only 4.2. The narrow range of responses fo r PNP implies that exceeding a threshold concentration would endanger a lar ge proportion of the aquatic community.