On June 29, 2015 the peer-reviewed scientific journal Chemosphere published a study by researchers from the University of Maine, U.S.. Heather Hamlin and colleagues investigated how keeping fish in polyethylene (PE) food contact material (FCM) plastic bags for 48 hours affected fish mortality. The PE plastic bags were intended for use as FCMs. Of the 10 fish (Pseudochromis fridmani) kept in one brand of bags, 60% were dead after 48 h. Hamlin and colleagues attribute the observed toxicity to nonylphenol (NP, CAS 104-40-5) levels of up to 160 μg/kg migrating from the PE bags into the sea water during two days. It is common to transport commercially available living aquarium fish in such PE bags, filled with sea water and oxygen.
NP is used in the manufacture of FCMs and can also be a non-intentionally added substance (NIAS), for example when the additive tris(nonylphenyl) phosphite (TNPP, CAS 26523-78-4) breaks down (FPF reported). In the EU, neither TNPP nor NP are authorized for use in plastic FCMs, but NP and 2,2′-methylenebis(4-methyl-6-nonylphenol) (MBMNP, CAS 7786-17-6) are known to be used in other FCMs, like rubber. In the U.S., NP, MBMNP and several related substances are authorized for use in FCMs. For example, NP polymerized with formaldehyde is used as ingredient in lubricating surfactants for the manufacture of FCMs. It is not known if MBMNP or lubricants are the source of nonylphenol migration.
NP is an endocrine disrupting chemical with estrogenic properties.
University of Maine (July 1, 2015). “Not all plastics equal.”
University of Maine (July 1, 2015). “Not all plastic created equal.” Youtube
Hamlin, H. J. et al. (2015). “Migration of nonylphenol from food-grade plastic is toxic to the coral reef fish species Pseudochromis fridmani.” Chemosphere 139:223-228.