China invites comments on suggested skin allergy and eye irritation testing methods
A report on the “Regulation Status of Domestic Non-Special-Use Cosmetics Related Animal Testing” prepared by Reach24h Consulting Group for Humane Society International sets out the testing method requirements that exist at present in China.
Ramping up regulatory efforts
Produced in May 2016, the report states that “the only source of test method accepted by CFDA [China Food and Drug Administration] is from Cosmetics Hygienic Standard (2007 version) and Safety and Technical Standard for Cosmetics, [which] will come into effect to replace it from 1st December 2016”.
As Troy Seidle, Vice President, Humane Society International, shared, before 2016, there were only testing methods present for the purposes of general toxicity.
In its 2016 report, a total of 13 In Vivo and 3 In Vitro testing methods were noted. These include the In vitro mammalian cell gene mutation test (OECD no. 476) and the In vitro mammalian cells chromosome aberration test (OECD no. 473).
At present, in a bid to bolster and secure the process of cosmetics safety evaluation and progress the cosmetics technical regulations, the Secretariat of the Cosmetic Standard Committee of Experts of the State Food and Drug Administration has organised and developed the "Skin Allergy in Cosmetic Products: Direct Peptide Test Method (Draft for Soliciting Opinions)” and "Method for Short Exposure of Chemical Raw Rabbit Corneal Epithelium Cell (STE) for Cosmetic Chemicals (Exposure Draft)".
We spoke with Troy Seidle, Vice President, Humane Society International, to talk us through the new potential testing methods and their impact on the cosmetics industry.
Direct Peptide Test Method (DPRA)
“The DPRA is an in chemico method designed to measure protein reactivity, by quantifying the reactivity of a test substance toward synthetic skin proteins,” Seidle explained.
There is a significant call to better understand the effects of protein reactivity on the skin as “exposure to a skin sensitising substance can lead to allergic contact dermatitis – a multi-step biological process that begins with the binding of a chemical with skin proteins”.
Once the percent peptide depletion of these proteins has been measured, the substance is categorised into “one of four classes of relative reactivity, for supporting the discrimination between skin sensitisers and non-sensitisers".
Currently one of three validated and OECD recognised non-animal methods for evaluating skin sensitisation, Seidle advocated the importance and necessity of all three of these as “each method evaluates a different aspect of the allergic skin reaction, and as such the methods must be used in combination as part of an integrated testing strategy”.
Strikingly, these non-animal methods have proven to be “much more accurate in predicting real-world risk for humans than animal tests in mice or guinea pigs (93% human predictivity using non-animal approaches vs. 83% human predictivity using mice)”, Seidle confirmed.
Method for Short Exposure of Chemical Raw Rabbit Corneal Epithelium Cell (STE)
This second method is a cell-based one that uses "rabbit corneal cells in culture”. After exposure to a test chemical that lasts five minutes, the STE test applies dye MTT to the cell cultures to “measure the number of viable cells present quantitatively based on the extent of the colour-change observed)”.
Potential adverse effects that are known to lead to eye damage are identified by decreased cell viability found during this measurement stage.
Similarly to the DPRA, the STE testing method is not a “1:1 replacement for the old animal test, but can be used as part of an integrated testing strategy to fully replace animal testing for eye irritation”.
This has particularly strong and relevant applications in countries that “accept other non-animal OECD eye irritation methods, such as the 3D human corneal model EpiOcular, or the corneal-based BCOP test; however, since the STE is the only non-animal method currently proposed for acceptance by NIFDC for cosmetics, full replacement will not be possible until additional eye irritation alternatives are accepted,” Siedle went on to explain.
Stakeholders have until 15th February to provide their feedback on these proposed non-animal testing methods.