Toxicological Evaluation and Limit Values for ... - Miljøstyrelsen

outes suggested that oral bioavailability of unconjugated nonylphenolwas about 20%. Analysis of the urine samples showed that about 10% ofthe oral dose was excreted in urine as unconjugated or conjugated nonylphenol,most of which was eliminated within eight hours. Only about1.5% of the oral dose was excreted in the faeces during the 56-hour collectionperiod.Müller (1997 - quoted in EU-RAR 1998) also measured the nonylphenolcontent of 25 samples of adipose tissue taken at autopsies of personsthought to have had no occupational exposure to alkyl phenols. Themeasured tissue concentrations were all within the range of backgroundcontamination found in the analytical "blank" samples. The author indicatedthat all reasonable precautions were taken to minimise contaminationduring analysis.Dermal contactNo data have been found. On the basis that nonylphenol appears to bereadily absorbed from the gastrointestinal tract, and in view of its highpartition coefficient, and since dermal LD 50 -values have been determinedfor NP and NPE, it is assumed that significant absorption via the dermalroute will occur. The limited dermal toxicity data that are available indicatethat the oral and dermal LD 50-values for nonylphenol are similar.2.2 EliminationSee above2.3 Toxicological mechanismsThere are no data on toxicological mechanisms for either NP or NPEwith the exception of oestrogenic effects of NP. NP is believed to interactdirectly with the oestrogen receptor (Odum et al. 1997).10