Within the KB-Program System Earth Management 2018 (KB-24-002-036) a pilot study was conducted into options to monitor of paraffin- or palmfat-like substances on Dutch beaches and in stomachs of corpses of beached Northern Fulmars. Such substances are, in part legally, discharged by tanker ships cleaning their tanks at sea.Paraffin was chemically identified by the presence of alkanes in the samples. It remains to be investigated in detail which other mineral oil derivatives may show similar alkane patterns. In the absence of alkanes further analyses were conducted to assess the type of material involved.Samples taken from beaches showed to be paraffin in 30 of 32 analyses (94%). One sample contained palmoil related substances, one sample remained unclear but contained phthalates (eg used as plastic softeners). The materials from bird stomachs proved to be different. Paraffin was only found in 31% of 32 samples. In 41% of the stomachs vegetable fatty substances were demonstrated, usually palm oil related. The remainder of samples had an uncertain mix of vegetable and animal fats. The difference between beaches and bird stomachs may have several backgrounds, including attraction for wildlife, melting points, and biodegradability.Over 20% of fulmars found in the Netherlands has chemical suspect materials in the stomach. Not much is known about potential health impacts. Over the years no clear changes can be detected. Quantities of material ingested are highly variable. Frequency of occurrence may slightly reduce over the more recent years, but there is no statistically significant trend. It would make sense to add records on chemical suspect materials in fulmar stomachs to the existing monitoring of plastics in the framework of OSPAR and the EU Marine Strategy Framework Directive. Clearly chemical analyses of substances encountered on beaches and in birds is additionally recommended.