PFAS Restrictions Rewriting Water Repellent Specifications Mid Season
Mid-season PFAS spec changes require re-engineering fabric density, adjusting curing parameters, and holding lot-traceable total fluorine CIC test evidence.
AATCC 118
Oleophobic Evaluation
Standardized laboratory protocols assess the resistance of finished fabrics to wetting by a series of liquid hydrocarbons. In this context, AATCC 118 provides a scale from zero to eight that allows finishing mills to verify the performance of fluorochemical treatments applied to apparel or upholstery. The grading depends on which hydrocarbon the fabric can support without absorbing it into the structure.
Hydrocarbon Scale
Test procedures require a set of eight hydrocarbon liquids with decreasing surface tension values. In AATCC 118, these liquids range from refined mineral oil, which has a higher surface tension, to pure n-heptane, representing the most aggressive wetting agent in the series. A technician deposits drops of each liquid sequentially on the fabric surface in a controlled temperature and humidity environment to check for wetting or absorption.
This progression determines the maximum level of repellent capability of the polymer finish. It ensures that the chemical treatment is fully active across the entire textile shipment.
Drip Application
Careful droplet deposition must occur under specific angle and height constraints to avoid dynamic impact effects. The observer monitors the interaction for thirty seconds to determine if wetting has initiated. If the droplet remains spherical and does not penetrate, the fabric passes that specific oil rating.
This test checks the boundary of the surface barrier without physical pressure.
Repellency Verification
Commercial transactions for high-performance workwear depend on these ratings to confirm spill resistance before fabrics leave the mill. Since oil droplets have much lower surface energy than water, passing AATCC 118 ensures a higher level of protection than simple water tests. It provides the definitive standard for industrial garment buyers who demand protection from oily soils.