Are current composting standards good indicators of whether a plastic is biodegradable?

Bioplastics proponents have promoted the use of composting standards (ASTM D6400 and EN13432) as indicators of plastics being biodegradable. However, these composting standards only require 90% biodegradation within 6 months in an industrial composting facility, whose controlled temperature, oxygen and humidity settings are unattainable by home composting. Thus, plastics that fulfil these composting standards are frequently not biodegradable under real-world open environment or home composting conditions. Consequently, composting standards are not good measures of whether a plastic is biodegradable.