GB/T 39951-2021 English PDF (GBT39951-2021)
GB/T 39951-2021 English PDF (GBT39951-2021)
GB/T 39951-2021: Evaluation method for degradability of disposable paper products
NATIONAL STANDARD OF THE
PEOPLE REPUBLIC OF CHINA
Evaluation method for degradability of disposable
ISSUED ON: MARCH 09, 2021
IMPLEMENTED ON: OCTOBER 01, 2021
Issued by: State Administration for Market Regulation;
Standardization Administration of the People's Republic of
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 4
4 Principle ... 5
5 Tests... 6
6 Evaluation rules ... 17
7 Test report ... 17
Annex A (informative) Example of biodegradability test system ... 19
Annex B (normative) Ecotoxicity test ... 20
Evaluation method for degradability of disposable
WARNING - Personnel using this Standard shall have practical experience working in a formal chemical laboratory. This Standard does not point out all possible safety issues. The user is responsible for taking appropriate safety and health measures and ensuring compliance with the conditions
stipulated by relevant national laws and regulations.
This Standard specifies evaluation methods for biodegradability, degree of disintegration and ecotoxicity of disposable paper products under aerobic composting conditions.
This Standard is applicable to evaluation for degradability of disposable paper products and raw materials such as diapers (sheets, pads), sanitary napkins (pads), wet wipes, paper cups, paper tableware, paper bags, paper boxes, pulp molded products. It is also applicable to paper-based composite materials and products.
2 Normative references
The following referenced documents are indispensable for the application 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.
GB/T 6682, Water for analytical laboratory use - Specification and test methods
GB/T 30903, Inorganic chemicals for industrial use - Determination of
impurity element - Inductively coupled plasma mass spectrometry (ICP-MS) 3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. 3.1 compost
passing through the 2mm test sieve to the total dry solids.
During ecotoxicity test, the compost obtained after the disintegration of the specimen is mixed with the reference culture soil in a precise ratio. Place in the tray. Evaluate the ecotoxicity of the specimen by inspecting the number of germination of seeds.
5.1 Biodegradability test
5.1.1 Reagents and materials
Unless otherwise specified, the reagents used in this Standard refer to analytically-pure reagents. Microbiology reagents shall meet the requirements of microbiology.
184.108.40.206 Water: GB/T6682, grade three.
220.127.116.11 Trace element solution: the solute concentrations are: boric acid: 500mg/L, potassium iodide: 100mg/L, ferric chloride: 200mg/L, manganese sulfate: 400mg/L, ammonium heptamolybdate: 200mg/L, ferrous sulfate:
18.104.22.168 Mineral solution: Measure 1mL of calcium chloride solution with a concentration of 0.1g/L, 1mL of sodium chloride solution with a concentration of 0.1g/L, 1mL of trace element solution (22.214.171.124). Weigh 1.0g of potassium dihydrogen phosphate and 0.5g of magnesium sulfate. Use water to set volume to 1000mL.
126.96.36.199 Compost extract: Use the compost produced in the composting device such as organic matter in municipal solid waste, garden and farmland waste to add into water. The mass volume ratio is 1:5. Place for 30min. Use a filter screen with a pore size of about 1mm or a medium-speed qualitative filter paper to filter and remove the residue. Or use a centrifuge to centrifuge at 1000r/min for 15min. Or directly use commercial special inoculants for composting. Prepare according to instructions for use.
188.8.131.52 Inoculum: Measure 500mL of mineral solution (184.108.40.206) and 500mL of compost extract (220.127.116.11). Mix well. Add 10.0g of peptone, 3.0g of beef dipping powder, 5.8g of urea, 20.0g of corn starch, 20.0g of cellulose powder.
18.104.22.168 Reference material: Use thin layer chromatography (TLC)
microcrystalline cellulose as a positive control reference material. The particle size is less than 20??m.
22.214.171.124 High-speed pulverizer: Speed is ???8000r/min.
126.96.36.199 pH meter: The reading is to the nearest of 0.1 or higher.
5.1.3 Specimen processing
Do not touch the specimen with hands. Wear clean powder-free protective gloves when processing specimens.
Cut the specimen into small pieces of about 10mm??10mm with scissors. Mix well. Use the high-speed crusher (188.8.131.52) to crush the fragments into flocs. Avoid specimen loss during crushing. Prepare three specimens. The weight of each specimen is within 30g~70g. Try to ensure that each specimen contains an integer number (pieces) of all the components of the specimen. If the mass of a single (piece) specimen is greater than 70g, then take 30g~70g of
specimen. Ensure that the specimens taken are representative.
NOTE: Specimens also include powder, granular or other simple shapes.
5.1.4 Test steps
184.108.40.206 Method A: Aerobic composting method
220.127.116.11.1 Determination of total organic carbon content
18.104.22.168.1.1 Total organic carbon content of specimen
According to the instructions for use of the total organic carbon analyzer (22.214.171.124), preheat and calibrate. Prepare another specimen according to 5.1.3. Use a balance to take 50mg~100mg (depending on the test range and accuracy of the instrument), to the nearest of 0.1mg. Put it into the high temperature resistant specimen cup for testing. Test for 10 times in total. Take the average of 10 test results as the total organic carbon content of the specimen. The result is rounded to 0.0001g/g.
126.96.36.199.1.2 Total organic carbon content of reference material
Refer to 188.8.131.52.1.1 to test the total organic carbon content of the reference material (184.108.40.206). Test twice in total. Take the average value as the total organic carbon content of the reference material. The result is rounded to 0.0001g/g. 220.127.116.11.2 Test preparation stage
18.104.22.168.2.1 Preparation of activated vermiculite
Mix the vermiculite (22.214.171.124) with the inoculum (126.96.36.199) at a ratio of 1:3 (mass : volume). Place it in the vermiculite activation reactor (188.8.131.52). Incubate at (50??2)??C for 3d~4d. If necessary, use water to make up to the initial mass by required moisture content by adding water or draining water, passing in wet air or dry air. If adjustments are made, the amount of carbon dioxide emitted shall be closely monitored. Compost cultivation until the specimen reaches the maximum level of biodegradation. The composting cycle generally does not exceed 6 months. If obvious biological decomposition can be observed, then the test period shall be extended to the constant plateau stage. If the plateau stage occurs earlier, that is, when the level of biodegradation no longer increases, then it can shorten the test cycle and stop the test.
NOTE: If the pH is lower than 7.0, it is because the easily decomposed sample quickly decomposes to acidify the compost, which will inhibit the biological decomposition of the material. To prevent acidification, it can increase the amount of compost in all compost containers. Or decrease the specimen, increase the compost, and repeat the test. 184.108.40.206.4 Carbon dioxide emission test
During the test, regularly use the carbon dioxide analysis equipment (220.127.116.11) to measure the carbon dioxide content in the exhaust gas of each compost container. Calculate the cumulative amount of carbon dioxide released. The number of measurements depends on the method used, the accuracy of the
required biodegradation curve, and the biodegradability of the specimen. If the measurement method of carbon dioxide analysis instrument is used, measure at least 2 times a day in the biodegradation stage. In the steady phase, measure at least once a day. The gas flow rate at the outlet shall be accurately measured. If the measurement method of sodium hydroxide absorption and release of carbon dioxide is used, then measure dissolved inorganic carbon once a day in the biological decomposition stage; in the stationary phase, measure 2 times a week.
18.104.22.168 Method B: Component analysis method
For multi-component products, the level of biodegradation of the product shall be calculated based on the level of biodegradation of each component
(material). For components with unknown level of biodegradation, then use method A (22.214.171.124) to determine the level of biodegradation of each component. Calculate the level of biodegradation of the sample according to 126.96.36.199, of which the mass of each component is accurate to 0.001g.
5.1.5 Calculation and presentation of results
188.8.131.52 Calculation of level of biodegradation of aerobic composting
184.108.40.206.1 Level of biodegradation of specimen
Calculate the level of biodegradation of specimen according to formula (1): 5.2 Disintegration degree test
5.2.1 Instruments and equipment
220.127.116.11 Compost container
The volume of the compost container shall be large enough (the smallest volume is 140L), so as to ensure that natural heating can occur. The material shall be made of strong, high-temperature resistant, and non-biodegradable materials. Does not affect the composting process or the quality of compost when used.
The bottom layer of the compost container has at least a 5cm thick drip plate to form a drainage system. Use suitable air supply system to provide adequate and continuous ventilation conditions for each compost container.
18.104.22.168 Temperature measuring equipment
The reading is to the nearest of 0.1??C.
22.214.171.124 pH meter
The reading is to the nearest of 0.1 or higher.
126.96.36.199 Oxygen test equipment
The reading is to the nearest of 0.1%.
Use a test sieve with a suitable shape and 2mm mesh.
5.2.2 Test steps
188.8.131.52 Test preparation stage
184.108.40.206.1 Preparation of biomass waste
Use the used biomass waste as carrier substrate. Try to take samples from the inputs of composting equipment that mainly treats municipal waste. The sample can also be directly sourced from biomass waste from households or grocery stores.
NOTE: The typical artificial biomass waste containing the following ingredients can be selected:
- Fresh fruit and vegetable mixed waste;
- Rabbit feed (seeds and extruded dried vegetable pellets);
four weeks, conduct once a week. Conduct once every two weeks after that until the test ends. If a specimen grid is used, open the grid and turn the ingredients inside.
Regularly measure the oxygen content of composted materials or the air
consumed. Measure at least once every working day during the first month of the test. Conduct once a week thereafter. The oxygen content in the composted material shall be higher than 10%. If the oxygen content is less than 10%, ventilate the biomass waste. The air flow rate per kilogram of total dry solids shall be less than 15L/h.
NOTE: Air flow can control the temperature and moisture content of the compost container. The air flow to ventilate the compost container shall be consistent with the actual composting equipment. If an excessively high air flow rate is used in practical applications, the amount of ammonia lost with the air can be supplemented by adding some substances (such as urea).
220.127.116.11.3 Moisture content and pH
After turning, take specimens from each test series to measure moisture content and pH. If the moisture content (mass fraction less than 40%) is too low, it will not be conducive to the normal progress of the composting process. Water shall be added at this time.
Measure the temperature in the middle of the compost, at least once every working day.
18.104.22.168 Termination of test
The cultivation cycle is 3 months.
22.214.171.124.2 Residual material
Use a 2mm mesh sieve to sieve all materials. Use running water to wash
carefully as much as possible. The washed pellets are dried to constant weight at 105??C (materials with a melting point lower than 105??C is at 40??C). Determine the total dry solids of fragments larger than 2mm.
Weigh the mass of the specimen collected in fragments larger than 2mm.
Compare with the mass of the starting specimen (126.96.36.199.2). Calculate the 5.4.2 Test methods
When fluorine content is measured, the specimen is calcined in a high-
temperature furnace at 1000??C for 15min under the condition of water vapor and oxygen. Collect condensate. Then use ion chromatograph to test.
Other elements are tested according to GB/T 30903.
6 Evaluation rules
6.1 If the product needs to provide proof of biodegradability (degradation) performance, a biodegradability test shall be carried out.
6.2 If the product needs to provide a certificate of compostability, it shall carry out biodegradability test, disintegration test and ecotoxicity test. The content of heavy metals, toxic and harmful substances in the product shall meet the requirements of Table 1.
7 Test report
The test report shall contain the followings:
a) Reference to this Standard;
b) Source of vermiculite and compost extract in the biodegradability test; c) Total organic carbon content of the reference material in the
biodegradability test and its biodegradation rate in 45d;
d) Total organic carbon content of the specimen in the biodegradability test and its maximum level of biodegradation;
e) Source of the biomass waste in the disintegration test and the results of all the analyses performed at the beginning of the test;
f) Degree of disintegration of the specimen in the disintegration test; g) Source of reference culture soil in the ecotoxicity test;
h) Germination rate of blank compost in the ecotoxicity test;
i) Ratio of germination number between compost specimen and blank
compost in the ecotoxicity test;
j) Content of heavy metals, toxic and harmful substances;
B.1 Simulation of reference culture soil
Any soil that can make seeds germinate and plants grow normally can be used as a reference cultivation soil. No additional fertilizer shall be added to the reference culture soil.
B.2 Sample preparation
Use 50% (mass fraction or volume fraction, stated in the report) compost and reference culture soil to prepare a mixture (sample). The "compost sample" is a mixture of the final product obtained after the disintegration of the specimen and the reference culture soil. The "blank compost" is the reference culture soil without adding the specimen after disintegration.
B.3 Plant species
Use mung bean and wheat in plant species to conduct eco-toxicity test
B.4 Test steps
Take at least 12 trays to test mung bean and wheat separately. Each plant requires 3 to hold compost samples and 3 to hold blank compost. Each tray is filled with at least 200g of sample (B.2). Add at least 100 seeds (B.3) on the upper surface. Use thin layer of inert material to cover seeds, such as silicate sand or perlite. Conduct three sets of parallel tests for each sample. Add water to 70%~100% of the water retention capacity. Regularly replenish the water lost due to evaporation throughout the test period.
NOTE: Tray size is about 30cm??20cm??5cm (length ?? width ?? height). During germination, place the tray in a dark place or cover it.
B.5 Result evaluation
Check the number of sprouts of compost samples and blank compost. Use the number value of plant germination to calculate the ratio of the number of sprouts between the compost sample and the blank compost, expressed in percentage. B.6 Validity of results