Chapter 09
Sourcing and grade
The same chemical name can be a food, a drain opener, or a pool cocktail. The grade is the product.
Read the percent. Read the extras. Fragrance, algaecide, corrosion inhibitors, aluminum chips, denaturants, and ‘boosters’ are how a useful compound becomes a junk drawer.
| If you will… | Buy… | Walk away from… |
|---|---|---|
| Treat drinking water with chlorine | Unscented 5–9% bleach, or 65–73% calcium hypochlorite granules | Scented / splash-less bleach; trichlor or dichlor tablets; shock blends with copper or algaecide |
| Put it in a mouth, on food, or on a plate | Food grade or USP | Masonry lime, pool DE, ice-melt blends, drain opener lye with extras |
| Make soap | 100% sodium hydroxide from a soap supplier | Hardware drain opener that lists aluminum or mystery surfactants |
| Wipe skin or a tool | 70% isopropyl USP, or 3% peroxide USP, or povidone-iodine | Denatured alcohol, 35% peroxide drums, iodine of unknown percent |
| Dust grain | Food-grade diatomaceous earth | Pool-filter DE |