The existence of several validated and accepted in vitro tests for the detection of severe eye irritants (tests with OECD Guideline) and the absence of validated and accepted in vitro tests for the detection of moderate irritants (no OECD Guideline yet) and non-irritants (only OECD 437/438) renders the evaluation of a reliable and meaningful testing strategy for in vitro eye irritation difficult. Industrial chemical companies are forced to establish their own ‘optimal’ testing strategy on an often poor scientific knowledge. This becomes even more of a challenge since in vivo testing is/will be restricted.
To overcome this issue, in 2012/13 toxicologists from some companies within the VCI have joined efforts to collect in-house data of ‘real-life’ test substances, focussing in a first step on data with the BCOP assay (Bovine Cornea Opacity and Permeability, OECD 437). In parallel, corresponding in vivo test results and results of other in vitro eye corrosion/irritation tests (e.g. EpiOcular, HET-CAM) for the test compounds were gathered where available.
The assessment of the collected data set was astonishing. No clear messages could be obtained for the development of a concerted testing strategy. There was no clear consistency among the in vitro tests within a battery approach, and/or some in vitro test results were in conflict with the available in vivo data.
Since the number of chemicals to be assessed solely based on in vitro data e.g. under REACH will strongly rise in the next years, it is urgent to establish reliable in vitro testing strategies, which require more knowledge on the applicability domain and the limitations of each in vitro test system. Thus, the data base with in vitro eye irritation/severe irritation tests should be enlarged for chemicals with reliable, existing in vivo data for eye irritation as a basis for further validation and for the establishment of reliable testing strategies specific to given chemical classes.
This project is looking to establish a substantial data base of in vitro eye irritation/severe eye irritation tests for chemicals with reliable, existing in vivo data. The ECETOC Eye Irritation Reference Chemicals Data Bank (ECETOC TR 48(2), 1998) or the Master Chemicals List currently established by Cosmetics Europe (Barroso et al, SOT Annual Meeting 2014, The Toxicologist 138, p. 268, No. 1027, 2014) could serve as a basis for the choice of test substances. Test systems being supposed are at least the BCOP assay and the ICE test for the detection of severe eye irritation and the HCE test and EpiOcular test for the detection of slight to moderate eye irritation.
The project’s objectives are to:
1. Define applicability domain and strenghts/limitations of the different in vitro systems included (in support of preparation of new OECD Guidelines or revision of existing OECD Guidelines)
2. Help to assess the reliability of the different in vitro eye irritation tests, e.g. with depending on different chemical classes, where applicable
3. Provide a first proposal for tiered testing strategies which enable industry to establish reliable in vitro test batteries for eye irritation assessment, specific to given chemical classes if appropriate, to ensure adequate classification & labelling, to improve eye irritation assessment based on in vitro data for C&L and e.g. REACH.
Determine in vitro eye irritation/severe eye irritation test systems of interest to be included in the project (proposal: BCOP, ICE, HCE, EpiOcular; further tests may be considered); studies should be conducted GLP-like (full GLP status not necessarily needed)
- Determine chemicals of different chemical classes and with different eye irritating properties to be included in the project e.g. based on the ECETOC Eye Irritation Reference Chemicals Data Bank (ECETOC TR 48(2), 1998) or the Master Chemicals List currently established by Cosmetics Europe (Barroso et al, SOT Annual Meeting 2014, The Toxicologist 138, p. 268, No. 1027, 2014)
- Determine fitting with ongoing stakeholder activities in this field to avoid overlap
- Determine laboratories to perform the given tests
- Test the chemicals chosen in the determined in vitro test systems (under GLP conditions and according to OECD Guidelines, if available, or according to the most recent standards); among selected laboratories test protocols must be harmonized to allow a comparison of the results
- Transfer results to ECVAM to promote validation with respect to the applicability domains of the respective test systems
- Establish testing strategies specific to given chemical classes, if possible
Download here the full version of the RfP LRI-AIMT6.