Standard No.:	GB/T 43287-2023
English Name:	Plastics—Determination of the degree of disintegration of plastic materials in marine habitats under real field conditions
Chinese Name:	塑料 在实际野外条件海洋环境中塑料材料崩解度的测定
Chinese Classification:	G31    Basic standards and general methods for synthetic resin and plastic
Professional Classification:	GB    National Standard
ICS Classification:	83.080.01 83.080.01    Plastics in general 83.080.01
Source Content Issued by:	SAMR; SAC
Issued on:	2023-11-27
Implemented on:	2024-6-1
Status:	valid
Target Language:	English
File Format:	PDF
Word Count:	11500 words
Translation Price(USD):	330.0
Delivery:	via email in 1~5 business day

Plastics - Determination of the degree of disintegration of plastic materials in marine habitats under real field conditions 1 Scope This document specifies test methods for the determination of the degree of disintegration of plastic materials exposed to marine habitats under real field conditions. The marine areas under investigation are the sandy sublittoral and the sandy eulittoral zone where plastic materials can either be placed intentionally (e.g. biodegradable fishing nets) or end up as litter due to irresponsible human behaviour. This depends on their physical characteristics, form and size of the materials, and on water currents and tidal movements. This document specifies the general requirements of the apparatus, and the procedures for using the test methods described. The determination of the level of disintegration of plastic materials exposed to pelagic zones such as the sea surface or the water column above the seafloor are not within the scope of this document. This document is not suitable for the assessment of disintegration caused by heat or light exposure. The described field test is a disintegration test and not a biodegradation test. Therefore, it cannot be used for demonstrating biodegradation or for making unqualified claims such as “biodegradable in marine environment” and similar. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3310-2 Test sieves - Technical requirements and testing - Part 2: Test sieves of perforated metal plate ISO 4591 Plastics - Film and sheeting - Determination of average thickness of a sample, and average thickness and yield of a roll, by gravimetric techniques (gravimetric thickness) ISO 4593 Plastics - Film and sheeting - Determination of thickness by mechanical scanning ISO 5667-3 Water quality - Sampling - Part 3: Preservation and handling of water samples ISO/IEC 17025 General requirements for the competence of testing and calibration laboratories ASTM E11 Standard Specification for Woven Wire Test Sieve Cloth and Test Sieves 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 biodegradation degradation (3.2) caused by biological activity, especially by enzymatic action, leading to a significant change in the chemical structure of a material [SOURCE: ISO 472:2013, 2.1680] 3.2 degradation irreversible process leading to a significant change in the structure of a material, typically characterized by a change of properties (e.g. integrity, molecular mass or structure, mechanical strength) and/or by fragmentation, affected by environmental conditions, proceeding over a period of time and comprising one or more steps [SOURCE: ISO 472:2013, 2.262] 3.3 disintegration physical breakdown of a material into small fragments [SOURCE: ISO 472:2013, 2.1757] 3.4 pelagic zone water body above the seafloor Note 1: Also referred to as the open water or the water column. Note 2: The surface of the pelagic zone is moved by wind-driven waves. It is in contact with the atmosphere and exposed to sunlight. With increasing depth pressure increase, temperature decreases, and light and surface wave energy are attenuated. 3.5 sublittoral zone coastal seafloor that is permanently immersed and extends from the low-water line to the continental shelf edge at 200 m water depth Note: The seafloor can consist of solid rock, or fragments that form sediments of different particle size, from coarse blocks and pebbles, to permeable sands, silt and clay. Sediments can form from fragmented rock or consist of fragments of biogenic origin (algae, shells, coral, etc.), or be a mixture of these compounds. 3.6 tidal zone borderline between sea and land that extends from the high tide line, which is rarely inundated with water, to the low tide line, which is typically always covered with water Note 1: The tidal zone is frequently a sandy area that is kept constantly damp by the lapping of the waves. Note 2: Stony and rocky shorelines also exist. Note 3: Synonyms are: eulittoral zone, midlittoral zone, mediolittoral zone, intertidal zone, foreshore. [SOURCE: ISO 22404:2019, 3.1] 3.7 total dry solids amount of solids obtained by taking a known volume of test material or compost and drying at about 105 °C to constant mass [SOURCE: ISO 472:2013, 2.1872] 3.8 volatile solids amount of solids obtained by subtracting the residues of a known volume of test material or compost after incineration at about 550 °C from the total dry solids (3.7) content of the same sample Note : The volatile solids content is an indication of the amount of organic matter present. [SOURCE: ISO 472:2013, 2.1889] 4 Principle The disintegration test is a real field test performed under natural environmental conditions in two different coastal regions. Concerned habitats are the eulittoral and the sublittoral zone where plastic materials can end up once dispersed in the sea. Note: Plastic materials predominately floating in pelagic zone are not covered by this document. The test material, preferably in the form of a film, is fixed in non-degradable plastic frames and both sides of the material are protected by a plastic mesh with limited defined mesh size (2 mm) in order to avoid sample loss once the disintegration process has started. Several frames with fixed test specimens are exposed to the eulittoral zone where the material is subjected to the tides and severely fluctuating weather conditions, and to the seawater - sediment interface in the sublittoral zone where less rough environmental conditions are likely to be expected. The disintegration is determined and reported after an exposure period of three years. However, the disintegration can be investigated in additional samples with exposure periods below or beyond three years, provided that the test procedure and the test evaluation are in accordance with this document. At the end of the exposure period, the disintegration of the test material is measured by means of removing the protection mesh and sieving the remaining material through 2 mm mesh sieve. The disintegration of the test material is evaluated by comparing the residual material (total dry solids) retained by the 2 mm sieve by the amount introduced (total dry solids). Alternatively, the disintegration of the test material can be determined as area loss (%) by means of image analysis (photogrammetry). Images of sampled test material specimen are analysed for the ratio between the disintegrated area versus total area of exposed film. Even if results from different exposure periods are available indicating a constant increase of the disintegration of a test material, it is not allowed to extrapolate the degree of disintegration beyond the maximum exposure period.