"the rate of degradation is very, very slow – untreated plastics of the type used in Future Posts degrade in the environment by 1.3um to 22um (0.0013mm/year to 0.022 mm/year for HDPE and LDPE respectively). For the mix of plastics typically in a Future Post, that means the post will degrade at a rate of around 10% of thickness of a hair every year"