Amsteel sling, exposed for 3 years in Nevada sun, breaks at at least 80% original strength.

Break test on Amsteel (1/8" Dyneema) sling, material left out to weather on top of Tinaja Peak for 3 years. The sample broke in the rope, not the splices, at ~80% of new strength. Ideally it should have been pulled to breaking slowly, but this was pulled behind my Jeep, and went from near 0 to full force in about 1 second.

The blue dye (urethane-carried) had faded some, likely from the intense UV in Red Rock at 4700'. The dye makes this Dyneema more UV-resistant than the material normally used in climbing slings (the latter is 35-50% nylon and has no UV protection except the stabilizers added in manufacture of the yarns).

3 years is a long time to wait, and I wish I'd put out more samples back then. Nowadays I coat any "exposed" Dyneema slings with several more layers of UV protection. I'm 67, and there are things I'd rather do now (than wait another 3 years).