The amnesty aims to tackle the increasing problem of nitros oxide canisters littering Warwickshire. The amnesty aims to tackle the increasing problem of nitros oxide canisters littering Warwickshire. AN AMNESTY for the safe disposal of nitrous oxide canisters has been launched in Warwickshire. Nitrous oxide canisters are increasingly being found discarded in parks, grass verges, and public spaces across Warwickshire. Do Not Bin Them: Under no circumstances should nitrous oxide canisters be placed in regular household waste or recycling bins.