z 7S Series All-Weather Cover vs Ultra- Sil Stuff Sack Set: which is safer?

Sea To Summit Ultra- Sil Stuff Sack Set is our pick: better on PFAS and on the overall hazard picture.

Keenz 7S Series All-Weather Cover

Keen

z 7S Series All-Weather Cover

PFAS grade

F 20/100

Overall grade

F 0/100

Verdict

Skip

Hazard flags

⚑ 4

Material

polyester/nylon with water-repellent coating

Confidence

45%

LikelyPFAS in water-repellent coating (reported in category; status unclear for this product)

PossibleAntimony in polyester (catalyst residue)

PossibleVolatile organic compounds (VOCs) from finish application

Our pick

Sea To Summit Ultra- Sil Stuff Sack Set

Sea to Summit

Ultra- Sil Stuff Sack Set

PFAS grade

D 65/100

Overall grade

analysis pending

Verdict

pending

Hazard flags

none flagged

Material

Ultra-Sil nylon fabric, no water treatment applied

Confidence

78%

Both products run through the same public rubric: materials, coatings, brand disclosure, lab findings, and recalls, plus a beyond-PFAS hazard analysis. Grades are model-based estimates, not lab tests. How grades work →

More waterproof outdoor accessories: see the full ranking