Risk assessment of cosmetic ingredients became a challenging exercise as experimental animals may not be used anymore. For most Annex substances, risk assessment was performed by calculation of the Margin of Safety as the ratio of the No Observed Adverse Effect Level (NOAEL)sys versus the Systemic Exposure Dose. The NOAEL mostly comes from oral rodent 90-day repeated dose toxicity studies. Since the implementation of the Cosmetic Regulation, the development of new Annex substances has stopped. The cosmetic industry tries to cope with this situation and in this context the International Cooperation on Cosmetics Regulation (ICCR) has launched the NGRA concept. Nine principles were published, underpinning the use of New Approach Methodologies (NAMs) in risk assessment of cosmetic ingredients.
NGRA is a human-relevant, exposure-led, hypothesis-driven risk assessment. It integrates in chemico, in silico, in vitro and in vivo data. Since all risk assessments are different, a precise descriptive list of tests is not realistic, but a number of guidelines are most helpful. NGRA uses a tiered and iterative approach starting with literature searches and data evaluation. It uses methods which are robust, relevant and transparently documented showing uncertainty. NGRA is now running on data-rich cosmetic compounds for systemic toxicity and sensitisation.
It will, however, take time to build up trust and provide training to toxicologists, especially if the methodology stays restricted to cosmetic ingredients.