A letter to the editor of the peer-reviewed journal Reproductive Toxicology was published online on 13th April 2017.
The publication of this letter is the latest achievement in a long scientific debate regarding a 2011 study by Danish researchers Julie Boberg and co-workers (1). This study is one of the key elements in the dossier for the classification of DINP under CLH, for which the public consultation is currently open.
However, as highlighted earlier by ECPI, this study contains a number of inconsistencies, typos and unclear reporting. As a result of ECPI’s questions, the authors of the paper published a corrigendum in 2016. This corrigendum, however, gave rise to additional questions, which are asked publicly in the current letter to the editor. Boberg et al.’s reply was published alongside our letter.
ECPI would like to remind all stakeholders that ECHA finalised an extensive risk assessment of DINP in 2014. Its conclusion was that the restriction on toys that can be placed in the mouth by children should be maintained, but that ‘no further risk management measures are needed to reduce the exposure of children to DINP […]’.
Complementing this risk assessment, Prof. Bridges and Dekant published in 2016 two papers on a Quantitative Weight of Evidence (QWoE) methodology.
In the first paper (2), they describe a quantification of the concept of WoE, for which regulatory bodies call in classification decisions. All available scientific evidence should be considered and balanced with respect to the quality of the research and the gravity of the effects observed.
In the second paper (3), Bridges and Dekant apply their method to toxicological data on DINP, comparing it to two other phthalates, DCHP and DnHP. They convincingly demonstrate that DINP classification as proposed in the current dossier is not warranted.
1 Boberg, J., Christiansen, S., Axelstad, M., Kledal, T.S., Vinggaard, A.M., Dalgaard, M., Nellemann, C. and Hass, U., 2011. Reproductive and behavioral effects of diisononyl phthalate (DINP) in perinatally exposed rats. Reproductive Toxicology, 31(2), pp.200-209.
2 Dekant, W. and Bridges, J., 2016. A quantitative weight of evidence methodology for the assessment of reproductive and developmental toxicity and its application for classification and labeling of chemicals. Regulatory Toxicology and Pharmacology, 82, pp.173-185.
3 Dekant, W. and Bridges, J., 2016. Assessment of reproductive and developmental effects of DINP, DnHP and DCHP using quantitative weight of evidence. Regulatory Toxicology and Pharmacology, 81, pp.397-406.