Essential ingredient in natural soap making. Formula NaOH. Sodium Hydroxide is considered 'Dangerous Goods' (UN1823) for transportation and restrictions for shipping apply. Essential ingredient in real soap making. This product is corrosive and should be handled in accordance with the labelling provided.We cannot 'post' sodium hydroxide, we have to send it by independent carrier, so a minimum charge applies.Include it as part of a larger order to ensure shipping charges are kept to our standard rates.