Soil burial test - appendix

Soil burial of plastics is considered one of the most severe laboratory tests run. Not only can microbial stains be observed, severe stiffening of polymers as well as cracking of the material can be seen. Weight loss in flexible PVC can be 10% or higher as well as severe cracking of polyurethane materials. 

Since the soil beds are very high in bacterial, actinomycetes, and fungi, a lightweight cotton control can be degraded in a matter of 7 days with a breaking strength loss of up to 90%. 

The soil burial test can be found under various designations worldwide. In the USA, one of the methods represented is ASTM D-3083 (ASTM, 1989) typical protocols would range from 30 to 90 days. 

See photographs below of polymeric stain and degradation after soil burial. 

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