COMMENTS ON THE SIDS INITIAL ASSESSMENT PROFILE FOR NONYLPHENOL

Submitted by
European Council for Alkylphenols and Derivatives (CEPAD)
Alkylphenols & Ethoxylates Research Council (APERC)
June 24, 2001

The following comments by the European Council for Alkylphenols and Derivatives (CEPAD) and the Alkylphenols & Ethoxylates Research Council (APERC) are presented on the nonylphenol (NP) draft SIAR/SIAP. CEPAD represents producers and suppliers of alkylphenols in Europe while APERC represents manufacturers, processors and users of alkylphenols and alkylphenol based products in North America.

GENERAL

The SIAR/SIAP contains a relatively comprehensive review of much of the available information on nonylphenol, but is largely based on the EU risk assessment. As such, it should be expanded to include analyses conducted in OECD countries outside of Europe. Specifically, the SIAR/SIAP does not reflect the extensive analyses conducted in the United States and Canada. Since the SIAP should be relevant and useful to all OECD member counties, the draft document should be amended to reflect analyses from other countries.

ENVIRONMENTAL EFFECTS

Predicted No Effect Concentration (PNEC) - The PNEC presented in the SIAR/SIAP was developed for use in the EU and is inconsistent with those developed by other OECD countries. For example, Table 5 from the draft Canadian Environmental Quality Guidelines document identifies several freshwater quality guidelines for nonylphenol from different jurisdictions. Some of these values are more than an order of magnitude greater than the PNEC developed by the EU and were derived in a manner consistent with the OECD guidance for "refined" PNECs. It is therefore suggested that the SIAR be modified to include these other water quality related guidelines.

Photolysis - The SIAP states that photolysis in water is "negligible." However, a study by Ahel et al. (1994) measured the kinetics of photochemical degradation of NP in natural waters. For NP, a photolysis half-life of 10 to 15 hours was measured in shallow surface water. These data indicate that photolysis is an important removal process for NP in shallow surface waters.

HUMAN HEALTH

Reproductive Effects - The human health section of the report suggest that the observed testicular and other reproductive effects may be significant. However, these effects have uniformly been seen at very high doses, often at levels that are fatal to the animals. We suggest either removing those studies that were conducted at near fatal dose levels, or at a minimum, including the following qualifying concluding paragraph from the EU risk assessment, (see page 176, section 4.1.2.9.4):

These concerns for reproductive toxicity are addressed in the risk characterisation, although there are uncertainties. The oestrogenic activity assays are merely screening tests. The effects on reproduction-related parameters in the multigeneration study were marginal and there was no evidence of functional changes in reproduction; furthermore any changes that were seen occurred at exposure levels in excess of the LOAEL for repeated dose toxicity (LOAEL for renal toxicity is 15 mg/kg/day, NOAEL for reproductive changes is 15 mg/kg/day). Evidence of testicular toxicity was reported in two repeated exposure studies designed specifically to investigate the effects on this organ, but only at doses which also caused mortality. No evidence of testicular toxicity was seen in standard repeated dose studies involving dietary administration. Development was not affected in a standard rat oral developmental toxicity study.

Bioaccumulation in Human Tissue - The SIAR states that there are insufficient data to allow a conclusion to be drawn on whether or not nonylphenol has the potential to bioaccumulate. To the contrary, there are numerous studies documenting that NP at doses below metabolic saturation (i.e., less than approximately 50 to 100 mg/kg body weight) is rapidly metabolized and excreted in mammals. There is ample evidence to conclude that bioaccumulation of NP is highly unlikely at anticipated exposure levels (ug/kg/day range).

Consumer Exposure - The SIAP states that consumers "may be exposed directly via ingestion and/or contact with pesticide products, cosmetics, pharmaceuticals (being phased out in EU), hair dyes and food (via migration from packaging polymers and papers)." As written, the document suggests that NP is directly used in these consumer products when NP itself is not used; the substances used are derivatives of NP, such as NPE and TNPP. Further, a growing body of research indicates that NPEs do not metabolize to NP in mammalian systems. (Knaak et al., 1966; Minami et al., 2000; Pedersen and Hill, 2000; Green, 2001).

OECD ASSESSMENT OF NONYLPHENOL ETHOXYLATES (NPE)

The document should reflect that the OECD SIDS assessment for NPE is under development by the U.S. It is expected that this assessment will be presented at a SIAM meeting in 2002. NPEs have been extensively tested and has shown minimal toxicity. In addition, no commercial NPE has been shown to have estrogen-like activity in the uterotrophic assay (Williams et al., 1996).

For additional information contact:

CEPAD:

Hans Certa
SASOL Germany GmbH
Building 1033/PB 02
Paul-Baumann-Str. 1
D-45764 Marl
(+49) 23 65 49 48 75
hans.certa@de.sasol.com

APERC:

Robert J. Fensterheim
Alkylphenols and Ethoxylates Research Council
1250 Connecticut Ave., N.W. Suite 700
Washington, D.C. 20036
USA
202/637-9040
info@aperc.org
www.aperc.org

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REFERENCES CITED:

Ahel M, Scully FE Jr, Hoigne J and Giger W. (1994) Photochemical degradation of nonylphenol and nonylphenol polyethoxylates in natural waters. Chemosphere 28: 1361-1368.

Knaak, J.B., Eldridge, J.M., and Sullivan, L.J. "Excretion of certain polyethylene glycol ether adducts of nonylphenol by the rat" Toxicol. Appl. Pharmacol. 9, 331 (1966)

Minami, Y., Iida, K., and Tajima, H. (2000). Absorption of a vaginal contraceptive, nonoxynol (polyoxyethylene nonylphenyl ether) and its metabolism to nonylphenol in female rabbits. Yakugaku Zasshi, 120, 298-303. Japanese except for abstract.

Pedersen, R. and Hill, E.M. (2000). Identification of novel metabolites of the xenoestrogen 4-tert-octylphenol in primary rat hepatocytes. Chem.-Biol. Interact. 128, 189-209.

 

 

 

 

 

 

 

 

 

 

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