Skin irritation – OECD 439

In vitro skin irritation test according to OECD 439 (RHE – Reconstructed Human Epidermis)

Skin irritation assessment is one of the essential regulatory requirements in the safety assessment of cosmetic, chemical, or biocidal products. In accordance with European requirements prohibiting animal testing for cosmetic purposes, validated alternative in vitro

The OECD 439 test is based on the use of reconstructed human epidermis (RHE) models and allows for the standardized assessment of the irritant potential of a substance or formulation applied topically.

Objectives of the analysis according to OECD TG 439

• Assess the irritant potential without using animals , on a relevant human biological model
• Classify a substance or mixture as “irritant” or “non-irritant” according to the GHS criteria (CLP, REACH, cosmetic regulation EC n°1223/2009)
• Meet national and European regulatory requirements (REACH, BPR, DIP)
• Contribute to the creation of a toxicological safety file (PSUR, cosmetic annexes, etc.)

Principle of the OECD 439 method

The test is based on measuring the cell viability of reconstructed human epidermis after direct exposure to the test substance. Residual viability is measured by the MTT test (ability of living cells to reduce a colored salt).

• Viability < 50% indicates an irritant effect (classification H315)
• A viability ≥ 50% classifies the product as non-irritant

Test duration : approximately 42 to 60 minutes of exposure, followed by a post-incubation period.

RHE models available

• EpiSkin®
• EpiDerm™
• SkinEthic™ RHE

These models are validated by EURL ECVAM and comply with international standards (OECD, ISO, BPR).

Products concerned

• Cosmetics: facial care, cleansers, sunscreens, pure active ingredients
• Chemicals (REACH, CLP)
• Biocides, pesticides, industrial formulations
• Topical medications, medical devices for cutaneous use

Results provided

• Viability rate (%)
• Regulatory interpretation (irritant/non-irritant)
• Before/After Photographs of the Model
• Full study report (GLP if required)

Why choose YesWeLab?

• YesWeLab connects you with partner laboratories specializing in in vitro GLP -certified platforms ISO 17025 accreditation , and experience in regulatory testing according to OECD 439.
• Our experts will assist you in choosing the protocol, validating samples and writing reports adapted to your regulatory obligations.

See also:

• In vitro skin absorption (OECD 428)
• In vitro eye irritation test (OECD 492)
• Skin corrosion test (OECD 431)