Glossary · Testing

In vitro testing and NAMs

What it means

Laboratory tests on cells, tissues or chemistry instead of animals, often called new approach methodologies. Examples are skin irritation on reconstructed human epidermis (OECD Test Guideline 439) and skin sensitisation tests under OECD Test Guidelines 442C, 442D and 442E.

Sources: 12345

Why it matters

Regulators and retailers expect this data before a product is placed on the market, and it feeds directly into the safety assessment and the product file.

How Guires CSL applies it

Guires CSL formulation, testing, clinical and regulatory teams work with In vitro testing & NAMs on client projects every week, from the first brief to the final product file.

Animal-free safety screening

Related terms

More in testing

Stability testing

Storage of a product at controlled temperatures, humidity and light to check that it keeps its look, smell, texture, pH and active content over its shelf life.

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Challenge test (preservative efficacy)

A test in which a product is deliberately contaminated with set microorganisms to check that its preservative system reduces them fast enough.

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References

  1. Regulation Regulation (EC) No 1223/2009 of the European Parliament and of the Council of 30 November 2009 on cosmetic products. OJ L 342, 22.12.2009, p. 59 (consolidated version 1 May 2026). eur-lex.europa.eu
  2. Standard OECD (2025). Test No. 439: In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method. OECD Guidelines for the Testing of Chemicals, Section 4. OECD Publishing, Paris. doi.org
  3. Standard OECD (2026). Test No. 442C: In Chemico Skin Sensitisation. OECD Guidelines for the Testing of Chemicals, Section 4. doi.org
  4. Standard OECD (2026). Test No. 442D: In Vitro Skin Sensitisation: ARE-Nrf2 Luciferase Test Methods. OECD Guidelines for the Testing of Chemicals, Section 4. doi.org
  5. Standard OECD (2026). Test No. 442E: In Vitro Skin Sensitisation: assays addressing the key event on activation of dendritic cells. OECD Guidelines for the Testing of Chemicals, Section 4. doi.org

Regulations and standards are listed first, then peer-reviewed literature. Sources checked October 2026.

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