Hydrolysis Resistance is the ability to withstand exposure to heat and humidity for an extended period of time. The test for Hydrolysis Resistance. ISO 1419 (Tropical Test Method C) is also commonly referred to as the Jungle Test. In the Jungle Test, material is subjected to a relative humidity of 95% and a temperature of 70° C (158° F) for several weeks then compared to the control sample for degradation.

There is no direct correlation of testing weeks to years of service in the field. The heat and humidity of the location will effect longevity. ACT (The Association for Contract Textiles) recommends that all polyurethanes meet or exceed 5 weeks of Hydrolysis Resistance to be considered for commercial upholstery use.