SIN List 2.0 methodology

S I N L I ST 2 . 0

Methodology The SIN (Substitute It Now) List has been developed to highlight the need for swift implementation of the REACH system for phasing out hazardous substances. This paper will explain how the SIN List has emerged and the methodology that has been used for selecting and evaluating substances for the 2.0 update of the SIN List.

Context and background Substances of Very High Concern within REACH

The SIN List

REACH is intended to provide basic information on industrial chemicals used in the EU and to limit the use of the most hazardous chemicals through either restriction or authorisation procedures. Very hazardous substances in REACH can be designated as Substances of Very High Concern (SVHCs) and they are subject to close scrutiny. The European Union has started the process of populating a list with these undesirable substances but so far only a few have been officially identified despite the fact that hundreds more are known via other EU agreed proces-

In order to ensure a strict and effective implementation of the REACH Authorisation procedure, ChemSec, in collaboration with leading public interest organisations in Europe and the United States, developed the SIN List1.

ses. SVHCs are divided into six different categories.

1. Carcinogenic [C] 2.

Mutagenic [M]

3.

Toxic to reproduction [R]

4.

Persistent, bioaccumulative and toxic [PBT]

5.

Very persistent and very bio-accumulative [vPvB]

All substances on the SIN List are identified by ChemSec as fulfilling the criteria for SVHCs as defined in the REACH regulation, and fall into at least one of the six categories above.

The SIN List 1.0 was released in 2008 and has since proven valuable in providing advance guidance for both companies and legislators when identifying and phasing out substances meeting SVHC criteria.

6. Equivalent level of concern, such as endocrine disruptors

Why focus on EDCs The body of evidence showing that endocrine disrupting chemicals (EDCs) may contribute to health and environmental problems is growing. EDCs interfere with the hormone system and have been increasingly linked to a range of health problems including cancer, diabetes, behavioural and attention deficit disorders, reproductive disorders and impaired fertility in humans and wildlife.

Endocrine disrupting chemicals can be found in a wide range of everyday products, from food packaging and cosmetics to cash receipts, toys and electric cables.

The possession of endocrine disrupting properties has not yet been cited as the primary reason for identifying a substance as a SVHC. This does not mean however, that EDCs are absent from the REACH candidate list. For example, four phthalates are on the candidate list due to their classification as toxic to reproduction, while HBCDD is on the list due to its PBT properties.

With the release of SIN List 2.0 and its specific focus on endocrine disruptors as chemicals of equivalent concern under REACH, ChemSec is putting EDCs in the spotlight and highlighting the need to include EDCs as SVHCs under REACH.

1. http://www.sinlist.org

S I N L I ST 2 . 0

Methodology for SIN List 2.0 During the development of the SIN List 1.0 endocrine disrupting properties were considered as one of many end-points, together with other hazardous properties. Of all the chemicals analysed, 30 chemicals in total were designated as substanc­ es of equivalent level of concern. Twenty-five of these were de­signated SIN List chemicals partly due to the evidence of endocrine disrupting properties. However, for the development of SIN List 2.0, only chemicals with endocrine disrupting properties have been considered.

Adding Substances of Very High Concern (SVHCs) due to their endocrine disrupting properties to the SIN List was a threestage process: 1. Screening of relevant substances 2. Literature research on selected substances 3. Evaluation against REACH criteria for SVHCs

First step – Screening phase The starting point was the European Commission’s database of potential endocrine disruptors2 developed under the “Community strategy for endocrine disrupters”. This database consists of 553 substances that have been evaluated with regard to their endocrine disrupting potential. The substances had been organised into three categories depending on the available information for each substance: • Category 1 – evidence in at least one study showing EDC properties in vivo • Category 2 – evidence in at least one study showing EDC properties in vitro • Category 3 – no evidence of endocrine disrupting activity or no data available.

However, since it would be neither relevant from a REACH perspective, nor possible from a practical point of view to assess all 553 substances, the selection needed to be reduced consider­ ably.

To narrow down the number of substances, it was decided to look only at the chemicals in the first two categories, category 1 and 2. They were seen as the most relevant since there was already indication of their endocrine disrupting properties. This reduced the number of substances down to 319.

Based on available information, it was clear that many of the substances in the list of 319 would not fall under the REACH regulation since many substances are not intentionally produced or imported. Several of these substances were by-products, transformation products of other substances, substances lacking CAS or EC numbers, or were substances already severely restricted in the EU. Examples hereof are dioxins, furans and PCBs. These substances were consequently excluded from the evaluation list.

Substances classified as CMR category 1&2 together with other substances already on the existing SIN List were also excluded in this step.

Further, an evaluation of possible uses for each substance was made. This evaluation was based on three sources. First, the assessments from the European Commission’s database were taken to identify uses as reported in the background documentation. Second, the Hazardous Substances Data Bank HSDB3 was used to get further information on potential uses. And finally, for the substances where no uses had been identified, a internet search was carried out to check if there were any other probable uses that had not been addressed by the first two sources.

Substances having no known uses according to the above mentioned sources were removed along with substances likely to be used only as intermediates or other use not relevant to REACH such as pharmaceuticals and registered pesticides.

To ensure consistency, these process and selection criteria were the same as those used during the development of SIN List 1.04 .

The application of these filters left a total of 41 substances to be assessed more closely by toxicologists with an expertise in endocrine disrupting chemicals. Important to mention is that the remaining substances that did not pass the above described filters should not be considered safe. We are aware of that following a strict protocol like this, we have overlooked substances with endocrine disrupting properties. Hence, the substances set aside, should not be considered safe.

2. EU COM EDC database: http://ec.europa.eu/environment/endocrine/strategy/substances_en.htm 3. HSDB, US National Institutes of Health: http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?HSDB 4. SIN List 1.0 methodology, http://www.chemsec.org/list/about-sin/methodology

S I N L I ST 2 . 0

Second step – Literature research The literature research phase was intended to give better understanding of the EDC properties associated with the selected substances by verifying the existing data from the European Commission EDC database as well as including the latest research on these substances.

The primary work of this phase was conducted by the members of the scientific staff of The Endocrine Disruption Exchange’s (TEDX)5. The process included a literature search, initial screening, abstract review, selection of studies, data entry and verification, and internal peer review.

Literature search: A comprehensive literature search in PubMed for each chemical was conducted. First, search terms derived largely from TOXNET synonyms for each chemical name were used. Results were downloaded to a reference database, then searched for endocrine-related studies using several wildcarded (*) search terms. Search terms were selected based on TEDx experience in reading endocrine related literature. The general approach was to be inclusive, using terms such as endocrine, hormone and receptor, as well as terms for the many organs involved in endocrine activity. Several terms that would target mechanisms of action at the genetic, cellular and molecular levels were also included. For a few chemicals, very little information was found on PubMed, and additional searches were performed in Web of Science and TOXLINE. Below is a list of the search terms used for every chemical.

Studies that could have escaped the search process would be those that had none of the following search terms in any search field (e.g., title, abstract, keywords).

Search terms: endocrin*, hormon*, receptor*, *estrogen*, *androgen*, *testosterone*, *thyr*, adrenal, *steroid*, *cortico*, cortisol, pituitary, hypothalam*, hippocamp*, pancrea*, islet*, insulin, testis, testes, testic*, thymus, thymic, prostate, ovar*, sertoli, leydig, follic*, LH, FSH, luteinizing, *natal*, gestat*, lactat*, sperm*, semen, oocyte*, oogene*, retinoi*, reprod*, *fertil*, ahr, ”aryl hydrocarbon”, *cyp*, *cytochrome*, PPAR*, ”peroxisome proliferat*”, rat, rats, mouse, mice, hamster*, ”guinea pig*”, guineapig*, murine, rodent*, human*, woman, women, men, man, child*, adolescent*, infant*, *school*, day-care, baby, babies, fetal, foetal, fetus, foetal, worker*, occup* , epidemiol*.

Initial screening: The literature search generated a list of publications for each chemical. The initial screening of these lists involved scanning abstracts to remove studies that were not published in peer-reviewed journals, did not represent original primary research, or were clearly irrelevant. For example, studies of pest control, remediation, analytical methods (for determining residues in tissues/fluids), and toxicokinetics

(e.g., metabolic fate, with no information on effects of parent compound) were removed at this level of screening. Review articlesand other secondary research were used only to locate further primary research.

Abstract review: The next level of screening involved reviewing abstracts of the studies that passed the initial screening.

Studies that were not peer-reviewed (e.g. presentation abstracts, letters to the editor) were removed during the abstract review. Most studies of human environmental exposure were removed at this level primarily because they were based on retrospective self report, failed to control for simultaneous exposure to other chemicals, and/or were unable to report any measure of exposure dose.

Selection of studies: Following the review of abstracts, remaining studies were downloaded for review. The goal was to select the studies that provided the strongest evidence for endocrine effects. In addition to the oestrogenic, anti-androgenic and thyroid-based effects that tend to be the focus of regulatory attention, evidence of hormonally-based mechanisms of action in other organs, glands and systems and at other levels of effects (e.g. gene expression, signalling mechanisms) was included.

Every effort was made to select the most scientifically robust studies. Studies that did not use appropriate control conditions or for which there were inconsistencies in the text or tables were not selected, with one or two exceptions where we made a note in our comments. When possible, research from several different research teams was included. On a few occasions, a team of researchers had published numerous articles on a chemical. In these cases, only a few were selected, including the first study, if it was particularly seminal, and/or the most recent study, if it represented a progression of increased knowledge over time (e.g. elucidating a detailed mechanism of action). No studies in which null findings directly contradicted significant findings from another study were found.

High dose studies measuring gross endpoints only (e.g. organ weights) in which the mortality rate was excessive were not selected. Exceptions were made for chemicals for which only high dose studies were available and there was evidence of an endocrine effect (not a toxic effect). Additionally, in some cases, effects were found only at the lowest doses studied. Such studies were evaluated carefully and were not rejected for this reason alone, as endocrine-related effects are known to exhibit non-monotonic dose responses.

Data entry and verification: Data from each study was entered into a spread sheet. Only statistically significant find­

5. The Endocrine Disruption Exchange: http://endocrinedisruption.com/home.php

S I N L I ST 2 . 0

ings were reported, with the rare exception of particularly compelling results for which no statistical analyses were conducted (e.g., gene arrays or changes in morphology). Null findings were reported only when they were relevant to the significant findings that were presented. In a few cases, a question mark was entered in the database to indicate uncertainty about whether the effects in a particular study were oestrogenic or anti-androgenic. With regard to dose, it was not always practical to present the full range of doses used, as some studies used complex experimental designs and others only reported relative binding affinity.

Internal peer review: The final analysis was conducted via a collaborative effort among the three primary researchers. The research team reviewed the chemicals one by one, evaluating each study in the database. The test methods employed were

discussed as well as the assays used, whether the effects were truly endocrine related, and how the authors interpreted their results. A summarised comment for each chemical was written during this process.

It was not unusual to read a study in which the authors never mentioned endocrine disruption, despite findings that were clearly relevant to the endocrine system. On this point, we relied on the principles of endocrinology - that endocrine effects encompass not only direct effects on traditional endocrine glands, their hormones and receptors, but also entire signalling cascades. These cascades affect reproductive function and foetal development, and also the nervous system, behaviour, immune system, liver, bone and many other organs and glands.

Throughout the review process, the decisions were guided by this global approach to the science of endocrine disruption.

Third step – Evaluation against REACH criteria for SVHCs The evaluation process to determine whether each substance fulfilled the REACH criteria for Substances of Very High Concern was led by ChemSec with support from an external group of scientists and toxicologists.

The existing REACH guidance document for preparation of an Annex XV dossier6 was used as basis for the SVHC assessment.

The guidance however, does not give clear criteria on how to do this beyond that it should be applied on a case-by-case basis. The guidance mentions few mechanisms and factors to be considered, and acknowledges that substances displaying endocrine active properties can result in changes in growth, development, reproduction or behaviour in the organism or in future generations.

The guidance document and the definitions developed for the European Commission database as well as advice from external

EDC experts were used as the basis for our assessment.

All eligible substances needed to have robust data, primarily from in vivo tests obtained through studies of documented endocrine disruption in actual and intact animals. This information was then complemented with in vitro data from experiments performed in test tubes and individual cells, as supporting evidence. To establish a reliable and robust dataset, at least three studies were needed with a minimum of two in-vivo studies, to qualify for in-depth evaluation.

Following this approach and the subsequent evaluation, 22 substances were identified as having strong enough evidence to be considered Substances of Very High Concern with regard to their endocrine disrupting properties.

remarks NOTE 1: It should be clearly stated that the screening criteria and method­ology applied does not capture all endocrine disrupting substances which could fulfil the SVHC criteria. Further, the chosen starting point, the European Commission database on EDCs, limited the number of substances to those suspected as EDCs when the list was drawn up in 1999. Therefore this list should not be considered as a final list, but merely a first step towards a more comprehensive list of EDCs as SVHCs. NOTE 2: The SIN List 2.0 only includes substances that are identified by

Concern. There are numerous other substances that are in fact endocrine disruptors, but either did not fall within the scope of REACH, such as pharmaceuticals and pesticides, or for which there was not enough evidence available at this point to justify being designated an SVHC. The substances not passing this conservative evaluation as SVHCs may still have strong indications of endocrine disrupting potential which should not be neglected and they should be further evaluated. [“Absence of evidence is not evidence of absence, Douglas G. Altman”]

ChemSec, Box 7005, SE-402 31 Göteborg, Sweden Tel: +46(0)31-711 04 95 E-mail: info@chemsec.org www.chemsec.org

ChemSec 110930

6. Technical guidance documents have been developed by ECHA in cooperation with stakeholders and EU Member States in order to provide guidance on how to interpret the legal texts in REACH. However, they are not legally binding documents. http://guidance.echa.europa.eu/public-2/getdoc. php?file=svhc_en

Illustrator: Christofer Ahde

ChemSec as fulfilling the REACH criteria of Substance of Very High