Risk Assessment

Having reviewed the safety of ingredients and formulations as well as estimated human exposure, the risk assessment is performed. The risk assessor evaluates the probability that adverse effects may occur when a product is used as intended or in ways that can reasonably be foreseen. In order for a product to be approved for use, the risk assessment must demonstrate that the product is safe for its intended use and that an adequate margin of safety exists even if it is misused in a foreseeable way. All the toxicological end points that are relevant to the conditions in which the product is used must have been adequately addressed.

In the best case, the risk assessment indicates that the ingredient or the product is ready to continue its journey towards the store shelves. However, if the risk assessment indicates that the ingredient or product does not meet P&G safety standards, the product will not be sold.

This process integrates the data obtained in Steps 2 and 3 to determine an acceptable exposure level for each new ingredient in a product. A common approach used is the Margin-of-Safety (MOS) approach and is illustrated by the following equation.

Margin-of-Safety = NOAEL/Exposure/Uncertainty Factors

In the MOS approach, a NOAEL (No Observed Adverse Effect Level) for any human health effects observed is calculated as explained in Step 3. The critical effect is then identified and used in the MOS approach. In the most simple of risk assessments, the NOAEL of the critical effect is then compared to the estimated level of human exposure and together these two values are used to calculate the MOS. It has been determined that an MOS > 1 is considered acceptable. Below is a sample calculation using the values calculated in Steps 2 and 3.

NOAEL (determined in Step 3) for Ingredient A for skin irritation in a facial moisturizer = 5 mg/cm².

The estimated exposure to Ingredient A (calculated in Step 2) = 0.2 mg/cm²

Margin-of-Safety = NOAEL/Exposure = 5.0 mg/cm²/0.2 mg/cm² = 25

The MOS is >1 and represents an acceptable level of Ingredient A in a skin moisturizer.

This example is simplified and it should be noted that the process may become more complicated if uncertainty arises in determination of the NOAEL or exposure levels. The MOS approach is generally used for non-cancer toxicity.

Read about the last step: Introduction of the Product and Post-Market Surveillance