Alchemist Liquid Oxygen H2O2 is composed of 34% hydrogen peroxide. Use with caution. Keep away from children. It is considered unlawful to sell, use or distribute this product in ways other than as claimed. Alchemist Liquid Oxygen H2O2 is composed of 34% hydrogen peroxide. Use with caution. Keep away from children. It is considered unlawful to sell, use or distribute this product in ways other than as claimed.