(The following may frighten you, but I promise that thousands of people make soap everyday without mishap. You need to know all the dangers present in order to avoid trouble. If you can get past the following warnings--you are destined to make soap!)
Look where drain cleaners are sold and buy 100% lye (Red Devil is one brand). Don't bother looking at liquid drain cleaners and don't try Draino (it contains metal). If you aren't sure the product is 100% lye, then order lye from a soapmaking or chemical supplier (addresses listed). Most good soap recipes list lye by weight for accuracy: lye in granular form (drain cleaner) measures differently than lye in flake form (the form of lye from laboratory chemical suppliers, pool chemical suppliers, etc). Scales are a necessary part of successful soapmaking and allows you to use any type of lye. Lye can be nasty if handled improperly. Lye (sodium hydroxide) is also known as caustic soda.
Upon opening a container of lye, the lye crystals absorb water from the air, which can weaken the strength of the lye and cause it to form a solid lump. When not in use, keep lye closely capped. Lye reacts with some metals: aluminum, zinc, and tin. Safe containers include heatproof stoneware, glass, enamel, stainless steel and plastic. Lye can be fatal if swallowed. Lye can remove paint. If lye, lye/water or freshly-made soap splatters onto a painted surface, wipe it off immediately. Wash the area with water and detergent; wash it with clear water, then wipe it dry. Lye, lye/water and freshly-made soap can burn and irritate skin. You'll notice itching before burning. Lye/water on skin is first noticed by a slippery feeling. Rinse your hands with vinegar and immediately rinse them with running water. Since lye can burn skin, you can imagine what it does to eyes. It's difficult to rinse your eyes while they're burning and you can't see. This painful and dangerous situation in entirely avoidable. Always wear eye protection! You may wonder why anyone wants to bathe with soap that contains something as harsh as lye. Well, the good news is that soap is *made* with lye, but soap doesn't *contain* lye. Lye reacts with fats, creating roughly three molecules soap and one molecule glycerin. The lye is no longer present--only great soap and glycerin.
Everyday, thousands of people make soap without mishap. In order to do so, you must be aware of all safety hazards. Children and feeble-minded people should not be in the soapmaking area or have access to stored soapmaking ingredients, especially lye and essential oil.
NOTE: If you have small children, keep lye (and essential oils) in a *locked* cabinet. Lye/water sitting at the edge of a counter can easily be reached by children and even swallowed. Drinking lye/water is like drinking liquid fire. Anyone ingesting lye/water should immediately be taken to an emergency room for treatment!