It is impossible to overstate the importance of safety when handling caustics. Many soapmakers have made soap for years and years without ever being burned. However, there are stories of family members drinking lye solutions, pets eating raw soap batter, and soapers not wearing goggles just once … all resulting in serious injury.

Lye soap is made at home all the time in complete safety. But your safety depends on the use of common sense. If you plan well, everything will go smoothly. The more soap you make, the more you will tailor your safety practices to your situation. Safety essentials are goggles and rubber gloves.

As mentioned earlier, lye is extremely caustic. When you first add the lye to the liquid, the resulting solution is also extremely caustic. After this lye solution is mixed with the soapmaking oils, however, the soap begins to neutralize, and becomes safe to touch after it has cured. Always wear goggles and rubber gloves when handling lye, lye solutions, raw soap, and fresh soap. If you are in doubt about how neutralized your soap is, err on the side of wearing goggles and gloves when they're not needed.

Testing for Neutrality

You can test for neutrality of soap in a number of ways. Using phenolphthalein or litmus papers is the most popular. Phenolphthalein is very reliable, inexpensive, and easy to use. You simply place a couple of drops of the solution on the soap you are testing. If the solution turns pink, it is alkaline. If it stays clear, it is neutral.

You can purchase litmus kits online and at your garden center. Follow the directions on the kit. Often it involves a color comparison chart on the box. You can also purchase an electronic pH meter. Soap is “safe” when it registers between 7 and 10 on the pH scale.

Caustic Messes

While your soap is curing, test it every so often for neutrality. If your soap is more than two weeks old and is still highly caustic, something went wrong in the measurements. The soap should not be used. Find out from your city or county what the proper disposal method is for caustic materials.

Keep a caustic mess contained until you can dispose of it properly. Line a heavy cardboard box with two heavy plastic garbage bags, one inside the other. Fill the box with clay kitty litter deep enough to absorb the mass. Wearing goggles and gloves, pour or scrape the caustic mass into the bags. Add an equal measure of vinegar. If the mass is soupy, add more litter. Label the box and store it in a safe place until you dispose of it.