TSP is a strong base and can cause severe eye damage and can burn unprotected skin.

Wear suitable clothing and eye protection. Keep away from skin and out of gloves.

Any foliage near where TSP is to be used should be soaked with plain water prior to the application of TSP, and rinsed down afterward. Be sure to read and follow all warnings on the product's packaging.

TSP is a very strong cleaner at the dilutions normally used, which vary from 1/2 cup TSP to 2 gal. warm water for "heavy duty cleaning" to 1 cup TSP to 3 quarts warm water for "ridiculously heavy duty cleaning" (source The Savogran Company). For mildew killing, household bleach is added to the TSP/water mixture. The recommended ratio is 1 part household bleach to 4 parts water.