Spray Rubber Sealant Coating, Waterproof, Clear, 14 oz vs Waterproofing Wax for Leather: which is safer?

Where these two actually differ

• We flag Volatile organic compounds (VOCs) and respiratory irritants during application, Coating degradation and loss of seal integrity over time, Skin or eye contact with uncured product and Leaching into water or food contact surfaces if misapplied on the Flex Seal and not on the Nikwax.
• We flag Respiratory irritation or fume inhalation during application and PFAS in water repellency treatment on the Nikwax and not on the Flex Seal.
• The Flex Seal is Proprietary rubber sealant coating, composition undisclosed where the Nikwax is wax-based waterproofing, 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 Flex Seal grade, at 35% confidence against 78%, because it discloses less.