Three in vitro skin sensitisation tests now available

Traditionally, skin sensitisation testing has been conducted using animal-based methods, but fully validated in vitro tests are now available. GLP accredited XCellR8 is one of only a small number of laboratories offering the complete panel comprising three major skin sensitisation tests: Direct Peptide Reactivity Assay (DPRA), KeratinoSens™ and human Cell Line Activation Test (h-CLAT).

The tests are fully accepted at a regulatory level to support discrimination of Skin Sensitisers and Non-Sensitisers in accordance with the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (UN GHS).

The current regulatory expectation for in vitro skin sensitisation testing is to adopt the “2 out of 3” approach, whereby 2 positive results out of the 3 tests (OECD TGs 442c, 442d and 442e) results in classification as a Skin Sensitiser.

Regulatory compliance

The tests are appropriate for compliance with a range of legislation including:

The 3 tests also provide a useful screen at non-regulatory stages of product development.

Unique to XCellR8: Animal-Product Free Adaptations of OECD Test Guidelines 442d and 442e

The standard KeratinoSens™ and h-CLAT tests include the use of animal-derived components in the test system, such as serum and antibodies. To provide our clients with truly animal-free tests, XCellR8 has adapted the methods to animal product-free conditions. Proficiency testing as per OECD Test Guidelines 442d and 442e has demonstrated our successful classification of a panel of reference chemicals in terms of skin sensitisation potential. ECHA (the European Chemicals Agency) has confirmed that the adapted tests are suitable for submissions under REACH. Following discussion at the OECD Expert Working Group on skin sensitisation at the end of 2016, they are currently under consideration by the WNT (National Co-ordinators’ Committee) for listing in OECD Test Guidelines 442d and 442e. Full technical reports on the Proficiency Testing and further regulatory details are available on request.

Direct Peptide Reactivity Assay (DPRA)

What the test is for

Provides classification as a Skin Sensitiser or Non-Sensitiser

What the test measures

Binding to skin proteins

OECD test guideline

442c

Turnaround time

2-4 weeks

Min. sample required

10ml (liquids) / 10g (solids)

KeratinoSens™ Test

What the test is for

Provides classification as a Skin Sensitiser or Non-Sensitiser

What the test measures

Activation of skin cells (keratinocytes)

OECD test guideline

442d

Turnaround time

4-6 weeks

Min. sample required

10ml (liquids) / 10g (solids)

h-CLAT Test

What the test is for

Provides classification as a Skin Sensitiser or Non-Sensitiser

What the test measures

Activation of immune cells (dendritic cells) in the skin

OECD test guideline

442e

Turnaround time

6-8 weeks

Min. sample required

10ml (liquids) / 10g (solids)

“The work is of an exceptionally high standard and with very fast turnaround times.”
REACH Consultant