Risk assessment
Our risk assessments take into account both the inherent properties of chemicals (hazard) and the way they are used (the exposure to the hazard) to determine if a product is safe. The internationally recognised formula to calculate risk is:
Risk = hazard x exposure
All risk assessments are undertaken by our Safety and Environmental Assurance Centre (SEAC). The welfare of vulnerable groups, such as young children, pregnant women and old people, is always taken into account. We keep a constant watch on scientific developments and review our findings in the light of new information.
Safe for people
We carry out safety risk assessments to establish whether products are safe for consumers.
First, we find out if there are any hazards associated with the ingredients in the products and then establish the level at which the ingredients have 'no effect'. For many commonly used ingredients we will already know the hazard and 'no effect' level, but for new ingredients we may have to identify potential hazards.
Second, we calculate the level of exposure to the ingredients (via skin, breathing, swallowing). This will depend on the type of product we are assessing and the amount of each ingredient in the product. For example, a person's exposure to ingredients in a skin cream will be higher than those in a laundry detergent. In this part of the risk assessment we also take into account the possibility of accidents or misuse of the product.
We then compare the predicted exposure with the 'no effect' level for any potential hazard. This gives us the margin of safety representing the risk for the user. Our experts make a judgement on the required margin of safety – taking into account a range of factors including the quality of the data and the nature of the hazard. We do not use an ingredient if the margin of safety is too small.
We also monitor the product in the market to confirm its safety. We do this by reviewing feedback from our consumer Carelines as well as information from poison centres.
Safe for the environment
We carry out environmental risk assessments to establish if our products are safe for the environment. We use accepted scientific techniques to work out the amount of our ingredients that will end up in the environment and whether this poses a risk of toxic effects. An example would be a threat to the health of fish in rivers. This assessment is done by estimating and comparing two concentrations.
First, the tonnage of each ingredient we sell in a country is matched with population demographics, water use and connection to sewage treatment. This helps us calculate a predicted environmental concentration (PEC) – the concentration of a chemical that ends up in the environment after use, for example when washing machine water goes down the drain. The PEC is largely influenced by the biodegradability of ingredients (the natural way organic materials are broken down into carbon dioxide, water and salts) and adsorption (adhering) of ingredients to particulate matter, such as sewage sludge. We have state-of-the-art testing facilities, including a purpose-built laboratory with small-scale sewage treatment plants to enable us to measure both biodegradation and adsorption.
Accurate data
In addition to estimating the PECs resulting from the use of chemicals in a specific type of Unilever product, we also estimate the total concentration of each chemical resulting from all the different products we make and other sources. For example, we work with other companies to assess the total releases of some chemicals into the environment, to gather more accurate data on total loads (see below). This helps us to determine our own impact in the context of society's wider emissions and the capacity of the environment to break them down.
Second, we calculate the predicted no-effect concentration (PNEC). This is the highest concentration of a chemical in the environment that has no adverse effects on plants or animals.
Ingredients are deemed safe if their predicted environmental concentrations (their PEC) are lower than those concentrations known to have no effect on the environment (their PNEC).
