Safety is the number one priority of the cosmetics industry. Safety doesn’t only mean human health, it also means ensuring that our products are safe for the environment after use.
From the brief developed by marketing, through the formulation process, to the use and disposal by the consumer, environmental fate matters. The way that products are formulated and used determines what goes down the drain. The individual properties of an ingredient in combination with its presence in the environment is the basis for estimating environmental risk.
What is Risk Assessment?
Hazard x Exposure = Risk
Hazard is a substance’s intrinsic potential to cause harm. For example, taking a walk through the countryside and coming across a bull is a hazardous situation. Naturally-occurring radioactive radon gas is a hazardous substance. Chemicals used in everyday products and situations can also have hazardous properties.
However, hazardous substances do not necessarily pose a risk of harm. The risk must be assessed by taking exposure into account. For example, if the bull is in the next field behind a fence, it poses a very low risk. Taking action to reduce exposure to radon significantly reduces the risk of adverse health effects. Properly managing any hazardous properties of chemicals in terms of the way the chemical is used, where it ends up, and at what level is vital to ensure that the potential to cause harm does not translate into likelihood of causing harm.
Principles of Environmental Risk Assessment
The principles of environmental risk assessment involve data gathering, hazard identification, exposure estimates and finally, a comparison of environmental exposure to known safe levels.:
- The chemical
- The environment
- The living organisms in the environment
The purpose of environmental risk assessment is to make sure that the concentration of the chemical in the environment is lower than the concentration which would have a negative effect on the environment and the life it supports.
How do cosmetic ingredients enter the environment?
Many cosmetic products are disposed down the drain after use. Considerations are made as to whether the water is treated by wastewater treatments plants or directly into the aquatic environment.
Evaporation and release to air must also be considered for certain volatile products
Predicting the environmental concentration
How can the concentration of a cosmetic ingredient in the environment be measured or predicted? Different pieces of information are required which take into account the amount going down the drain and what happens to the ingredient in the environment; for example, whether it biodegrades, what happens to it in water treatment plants and which locations it travels to.
- Volume information – how much product is used and released by consumers?
- The physchem properties of the ingredient - how it deposits between soil, sediment, water and the atmosphere.
- An understanding of what happens to the ingredient in the environment – data from internationally standardised tests demonstrating that it biodegrades under appropriate conditions.
- Specially developed computer models are available which take into account a large number of variables to estimate the environmental concentration of chemicals
Predicted environmental concentrations are usually used rather than actual measurements of how much of the chemical is in the environment. A measurement only provides one snapshot in time whereas a prediction based on a model is cheaper and covers different scenarios, locations and conditions.
Predicting the no-effect concentration
Ecotoxicity testing is used to understand the level of a substance in the environment which will not cause adverse effects for different species.
One of the fundamental ways in which environmental risk assessment differs from human health risk assessment is that in the environment, many more species are involved and the risk assessment is looking at protecting a population rather than an individual.
Historically, in vivo tests were relied on to derive the predicted no effect concentration. However, non-animal alternative tests are now available for many endpoints, and more are in development.
If it isn’t possible to derive a predicted no-effect concentration, the EcoTTC concept may be used. TTC stands for Threshold of Toxicological Concern and it is a generic, very low concentration value based on historical data, below which there would be no appreciable ecotoxicity risk for the majority of chemicals. There are different TTC values for cationic and non-cationic chemicals based on the different hazards presented by these two classes.
The TTC concept is intended to be used for screening purposes and rapid decision making and the ecoTTC has been developed specifically for the home and personal care sectors. Further information can be found at Gutsell et al (2015).
Determining the risk
When information is available on the environmental concentration of an ingredient, and the concentration at which the substance will not cause harm in the environment, it is possible to determine the risk. The risk is basically the ratio between the real-life environmental concentration and the concentration which is safe for the environment.
If this ratio is less than one, the substance is safe and the risk assessment is complete.
If this ratio is more than one, further investigations must be conducted, such as a refined risk assessment or an alternative ingredient.
Risk assessments often follow a ‘tiered approach’. Level one, or the most basic tier, requires the least data and the least sophisticated methods, but is also the most conservative and could therefore overestimate the risk. Higher tiers use more refined models and require a better quantity and quality of data, but the output will be more realistic.
If an ingredient fails a lower tier risk assessment, it is usually then assessed through a higher tier risk assessment using additional, more refined data. This higher tier risk assessment will give a less conservative and more realistic result.
Example of considerations that might change in a tiered model for exposure assessment: