In reply to paulcarey:
I would strongly consider retiring the harness. The general advice for soft-goods is 10 years maximum - much less for extreme wear. Harnesses are not super expensive items, and being able to trust your equipment 100% is nearly as important as whether it would actually be safe - the fact you have asked whether it's safe shows that you don't trust it 100%.
In saying that - from what I understand, recent tests showed that nylon holds up pretty well as long as it's not exposed to UV or harsh chemicals. As long as there's been no solvents nearby, or acids / bases, and it was in complete darkness - it's probably okay (at least the nylon part anyway).
Post edited at 17:06