Chemical burns can cause deep injury and subsequently significant scarring to the skin. The mechanism and pathophysiology of chemical burns is distinct to thermal burns, and recommended first aid approaches are consequently different. Twenty minutes of cool running water is an effective first aid measure to improve outcomes after thermal burn. For chemical burns to the skin, the recommendations are immediate water lavage for 60 min, removal of contaminated clothing if not stuck to the skin and then covering the wound with a sterile dressing. This review assesses the peer-reviewed literature to find the evidence behind the efficacy of cutaneous chemical burn first aid on short term outcomes such as length of hospital stay, depth of burn and longer-term outcomes such as scarring; in particular, the effect of immediate or early water lavage, and the effect of the duration of water lavage. Ocular chemical burns were not included in this review. The review suggests some evidence to support that the early application of cool water irrigation may reduce length of hospital stay and the extent of scarring. Community education should emphasize that water irrigation is recommended and that the earlier this happens, the better.