Waterproofing Wax for Leather vs 303 Fabric Guard: which is safer?

Where these two actually differ

• We flag Respiratory irritation or fume inhalation during application and PFAS in water repellency treatment on the Nikwax and not on the 303 Products.
• We flag PFAS in formulation and environmental persistence, Inhalation of aerosol propellant and volatile solvents, Skin and eye irritation from concentrated spray and Residual coating buildup and fabric stiffening over time on the 303 Products and not on the Nikwax.
• The Nikwax is wax-based waterproofing where the 303 Products is Fabric treatment coating (water and stain repellent), which is most of the difference in these two grades.
• The gap is 25 points, wide enough that this is not a close call, and the Nikwax is the one to buy.
• We are less certain about the 303 Products grade, at 45% confidence against 78%, because it discloses less.