How do I handle lye safely?
Short answer
Always add lye slowly to cold liquid, never the reverse. Wear full protective gear and never change a calculated lye amount.
Explanation
The book treats sodium hydroxide with extreme respect. Store it locked in a dry, cool place, double-contained in an HDPE bucket with hazard labels. The rule is sacred: lye to liquid. Add the granules slowly to cool liquid in a deep, resistant container while stirring. The solution heats up fast and releases fumes you must not inhale. Chilling or partly freezing the water reduces the heat spike.
Weigh lye to 0.1 g, and never adjust it without recalculating the whole recipe.
What to do
- Wear goggles, nitrile gloves and long sleeves, and work with ventilation.
- Pour the lye solution into the oils through a sieve.
- Run every recipe through a lye calculator; the book recommends SoapCalc.net.
Source: The Big Book of Homemade Soap — The Non-Negotiable Protocol: Chemical & Ingredient Handling