ASTM D7991-22
Standard Test Method for Determining Aerobic Biodegradation of Plastics Buried in Sandy Marine Sediment under Controlled Laboratory Conditions

Standard No.

ASTM D7991-22

Release Date

2022

Published By

American Society for Testing and Materials (ASTM)

Latest

ASTM D7991-22

Scope

1.1 This test method determines the biodegradation level of plastic materials exposed to laboratory conditions that simulate the environment found in the sandy tidal zone. 1.2 The tidal zone, that is, the part of the coast affected by the tides and movement of the waves, is the borderline between sea and land, frequently a sandy area that is kept constantly damp by the lapping of the waves. Stony and rocky shorelines also exist. 1.3 Plastic marine debris is frequently washed up in this habitat where it must be removed in order to restore the original landscape. 1.4 It is of interest to know the biodegradation behavior of plastics when exposed to conditions simulating this habitat, because this information can help in predicting the time needed for the biodegradation of the litter. 1.5 Biodegradation is determined by measuring the CO2 evolved by the plastic material when exposed to a sediment kept wet with salt-water in a reactor, to simulate the tidal zone. 1.6 Marine fresh-water habitats (for example, those found in brackish waters and estuaries) are not considered by this standard. 1.7 Reports shall clearly state the percentage of net CO2 generation for both the test and reference samples at the completion of the test. Furthermore, in the laboratory reports, the results shall not be extrapolated beyond the actual duration of the test. NOTE 1—There is no known ISO equivalent to this standard. 1.8 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.10 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

ASTM D7991-22 Referenced Document

• ASTM D5988 Standard Test Method for Determining Aerobic Biodegradation in Soil of Plastic Materials or Residual Plastic Materials After Composting
• ISO 8245 Water quality - Guidelines for the determination of total organic carbon (TOC) and dissolved organic carbon (DOC)

ASTM D7991-22 history

• 2022 ASTM D7991-22 Standard Test Method for Determining Aerobic Biodegradation of Plastics Buried in Sandy Marine Sediment under Controlled Laboratory Conditions
• 2015 ASTM D7991-15 Standard Test Method for Determining Aerobic Biodegradation of Plastics Buried in Sandy Marine Sediment under Controlled Laboratory Conditions