Side-by-side comparison
Valspar Prep Step Whole House Primer Flat Tintable White vs Sherwin-Williams LOXON Water Blocking Primer/Finish Flat White
| Fact | Prep Step Whole House Primer | LOXON Water Blocking Primer/Finish |
|---|---|---|
| Use | Exterior primer | Exterior primer, Interior primer |
| Sheen · base | Flat · Tintable White | Flat · White |
| VOC (untinted) | <50 g/L | 0 g/L |
| VOC added by tint | Not stated | Not stated |
| Emissions testing | Not documented | Tested (GREENGUARD, LEED emissions) |
| Health certification | None found | None found |
| Safety Data Sheet warnings | 3 | 1 |
| Ingredient disclosure | Safety Data Sheet only | Partial (environmental data sheet) |
| Safety Data Sheet revised | 8/18/2026 | 8/18/2026 |
Highlighted rows are where the two products differ. Facts come from each maker's documents; "not disclosed" means the maker hasn't published it, not that the product failed a test.
See the score broken down by category
Free. Answer 4 quick questions and create your account.
Scores summarize the evidence makers publish. They don't guarantee safety or predict individual health outcomes. How we score
Sources
Valspar Prep Step Whole House Primer
Sherwin-Williams LOXON Water Blocking Primer/Finish