A UV stabilizer is a product which is designed to prevent or slow degradation caused by exposure to ultraviolet radiation. Exposure to sunlight causes products to break down over time, and in many products, they do so in a chain reaction process, with the rate of decay accelerating over time as more and more of the product is broken down. Degradation caused by UV exposure can be a serious problem with a wide range of products, and is generally undesirable.
Plastics, synthetic rubber, and similar products are often treated with a UV stabilizer or have the stabilizer integrated into their manufacture. The concentration of the stabilizer varies, depending on how it acts and the specific needs of the product. Once stabilized, the product can still decay, but the process will be slowed. Especially if combined with sensible care, a UV stabilizer can extend a product's lifetime significantly.
Ultraviolet absorbers (UVAs) act by absorbing UV radiation before it reaches the product. These products need to be used in high concentrations to be effective, as otherwise they will not be able to absorb enough light to preserve the product. Hindered amine light stabilizers (HALS) work by trapping free radicals generated during the oxidation process, effectively halting the chain reaction which allows degradation to occur. These stabilizers can be added in lower concentrations because only a small amount is needed to be effective.
Adding a UV stabilizer can make a product more expensive, but this is viewed as an acceptable tradeoff because the product will last longer, justifying the increase in price. This can be an important safety issue in addition to a consumer one, as when some products decay, it can lead to dangerous conditions which could expose people to risk. Degradation caused by light exposure can also simply be a nuisance, as for example when a convertible roof leaks.
A wide range of UV stabilization products are available to people who need them. Many are manufactured by chemical companies and designed for specific applications, such as addition to plastic products to help them resist breakdown when they are used outdoors. It is also possible to order custom products for specific applications, although such products can be expensive if they are not in the regular product lineup of a manufacturer. Care must be taken when working with a UV stabilizer because some contain toxic components or will release hazardous materials when blended with the wrong products.