Plastics are now used for many piping applications in construction, but can be vulnerable to weathering by the action of UV light. This Information Paper summarises work to evaluate the resistance of plastics pipes to artificial weathering. Most of the pipes and fittings tested discoloured severely, and became embrittled. However, some were affected much more severely then others, suggesting that weathering resistance could readily be improved if required. Plastics pipes should not be stored exposed to sunlight for prolonged periods unless known to be resistant to UV light. When specifying plastics piping systems, consider whether any parts will be exposed, establish whether the system is resistant to UV exposure, and take protective measures if appropriate.