GB/T 35612-2024Green product assessment - Wood-plastic composites (English PDF)

Foreword Foreword

The document is drafted in accordance with the rules given in GB/T 1.1-2020, Directives for standardization—Part 1: Rules for the structure and drafting of standardizing documents.

It replaces GB/T 35612-2017, Green product assessment—Wood-plastic composites. Apart from structural adjustments and editorial changes, the main technical changes are: the definition of green wood-plastic products has been changed (3.1, against 3.1 of the 2017 edition); the basic requirements have been changed (4.1.4 and 4.1.6 to 4.1.7, against 4.1.1 to 4.1.3 of the 2017 edition); a classification of the benchmark values of the assessment indicators has been added, together with the environmental attribute of whether a wastewater treatment installation is present, the quality attributes of the migration limits for harmful elements, of the mould resistance and of the durability of the mould resistance, and the low-carbon attribute (Table 1); the benchmark values for the addition rate of recycled raw materials under the resource attributes, for the environmental performance of the packaging and for the flame retardant under the quality attributes have been changed (Table 1, against Table 1 of the 2017 edition); the heavy metals of the substrate or co-extruded layer and the heavy metals of the coated layer, limited to coloured paint, have been deleted from the quality attributes (Table 1 of the 2017 edition); and the assessment method has been changed (Clause 5, against Clause 5 of the 2017 edition).

The document was proposed by the China Building Materials Federation and is under the jurisdiction of the National Technical Committee on Lightweight and Decorative Building Materials of Standardization Administration of China (SAC/TC 195). It was first issued in 2017, and the present edition is the first revision.

1 Scope

The document lays down the assessment requirements and the assessment method for the green product assessment of wood-plastic products.

It applies to the product assessment of green wood-plastic products.

2 Normative references

The following documents are cited normatively in the text and their content constitutes indispensable provisions of the document. For dated references only the edition cited applies; for undated references the latest edition, including all amendments, applies.

GB/T 2589 General principles for calculation of the comprehensive energy consumption; GB/T 7119 Evaluating guide for water saving enterprise; GB 6675.4-2014 Safety of toys—Part 4: Migration of certain elements; GB/T 15337 General rules for atomic absorption spectrometric analysis; GB 17167 General principles for equipping and managing the measuring instruments of energy in organization of energy consumption; GB/T 17657-2022 Test methods of evaluating the properties of wood-based panels and surface decorated wood-based panels; GB/T 18455 Packaging recycling marking; GB 18580 Formaldehyde emission limits for wood-based panels and their products used in interior decoration and refurbishment materials.

GB/T 19001 Quality management systems—Requirements; GB/T 22048 Toys and children's products—Determination of certain phthalate plasticizers; GB/T 23331 Energy management systems—Requirements with guidance for use; GB/T 24001 Environmental management systems—Requirements with guidance for use; GB/T 26125 Electrical and electronic products—Determination of six regulated substances, namely lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls and polybrominated diphenyl ethers; GB/T 29365-2012 Wood-plastic composites—Method of artificial weathering test; GB/T 29899 Determination of the release of volatile organic compounds from wood-based panels and their products—Small chamber method.

GB/T 32161 General principles for the assessment of eco-design products; GB/T 33761 General principles for green product assessment; GB/T 35469-2017 Test method for the mould resistance of wood-plastic composites for building; GB/T 37837 General rules for quadrupole inductively coupled plasma mass spectrometry; GB/T 45001 Occupational health and safety management systems—Requirements with guidance for use; GBZ 1 Hygienic standard for the design of industrial enterprises; GBZ/T 189.8 Measurement of physical agents in workplace—Part 8: Noise; GBZ/T 192.1 Determination of dust in the air of workplace—Part 1: Total dust concentration; JC/T 2222 Terminology of wood-plastic composites; LY/T 2554 Determination of the biomass content of wood-plastic composites—Fourier transform infrared spectroscopy.

3 Terms and definitions

The terms and definitions given in GB/T 33761 and JC/T 2222 and the following apply.

3.1 Green wood-plastic composites: wood-plastic composite materials and the products made from them that, over the course of their life cycle, meet the requirements of environmental protection, do no harm or little harm to the ecological environment and to human health, consume little in the way of resources and energy, are of high quality and have low carbon emissions.

4 Assessment requirements

4.1.1 Basic requirements. The state of the pollutant discharge of the producing enterprise is to conform to the relevant environmental protection laws and regulations and to meet the requirements of the national or local pollutant discharge standards, and the enterprise is to have had no major or greater safety or environmental pollution incident in the past three years.

4.1.2 The discharge of wastewater and of air pollutants by the producing enterprise is to meet the national and local discharge standards and the requirements on total quantity control and on the pollutant discharge permit.

4.1.3 The producing enterprise is to set up and operate an environmental management system, a quality management system, an energy management system and an occupational health and safety management system in accordance with GB/T 24001, GB/T 19001, GB/T 23331 and GB/T 45001.

4.1.4 The producing enterprise is to be equipped with energy measuring instruments in accordance with GB 17167, and with environmental protection installations and pollutant detection and on-line monitoring equipment as required by the environmental laws, regulations and standards.

4.1.5 The producing enterprise is to use the advanced processes and techniques that the State encourages, and is not to use techniques, processes, equipment or related materials that the State or the relevant local government departments have restricted or phased out.

4.1.6 The producing enterprise is to carry out the eco-design of wood-plastic products in accordance with the relevant requirements of GB/T 32161. Following the life cycle approach, the durability, reliability, reusability, remanufacturability and ease of recovery of the product are to be taken into account at the design and development stage, so that the effect on resources and the environment of the choice of raw materials, of production, sale, use, recovery and disposal, and of each of the other links, is lessened.

4.1.7 Green wood-plastic products are to meet the requirements of the highest grade of the corresponding product quality and safety standards.

4.2 Requirements on the assessment indicators. The indicator system is made up of first-level indicators and second-level indicators. The first-level indicators are the resource attribute indicators, the energy attribute indicators, the environmental attribute indicators, the quality attribute indicators and the low-carbon attribute indicators. The indicator system for green benchmark wood-plastic products and for green wood-plastic products is to meet the requirements of Table 1.

Table 1, Requirements on the assessment indicators and the basis of judgement, has columns for the serial number, the first-level indicator, the second-level indicator, the unit, the benchmark value for green benchmark wood-plastic products, the benchmark value for green wood-plastic products, and the basis of judgement. It carries thirty-five numbered lines. The second-level indicators are, under the resource attributes: the reuse rate of process water; the addition rate of recycled raw materials; the recovery and utilization rate of waste wood-plastic products; the source of the wood and bamboo fibre; the content of wood and bamboo fibre; and the packaging of the product. Under the energy attributes: the comprehensive energy consumption per unit of product. Under the environmental attributes: whether a dust recovery installation is fitted; the particulates in the production shop; the noise in the production shop; harmful substances in the product packaging; whether a wastewater treatment installation is present; lead salt stabilizers; phthalates; flame retardants; formaldehyde emission; and volatile organic compounds over 72 h. Under the quality attributes: the migration limits for harmful elements; the ageing resistance of the product; the mould resistance; the durability of the mould resistance; and the resistance to boiling water. Under the low-carbon attributes: the service life of the product, and the product carbon footprint report.

The benchmark values of Table 1 are not reported here. In the extracted text the indicator names, the units and the two columns of benchmark values are printed as separate runs that do not match line for line — for the first three indicators alone, three units are followed by four value entries — so the values could not be paired with the indicators and with the two product grades.

The basis of judgement given for each indicator is legible and is as follows. The reuse rate of process water is calculated in accordance with GB/T 7119, with a report, statistical returns and original records provided as evidence. The addition rate of recycled raw materials is calculated in accordance with A.1, with the purchasing and use lists provided. The recovery and utilization rate of waste wood-plastic products is calculated in accordance with A.2, with recovery certificates, technical documents on the recovery process and a description of the routes and channels of recovery. The source of the wood and bamboo fibre requires the purchasing lists of raw materials and evidence of the quantity added. For the content of wood and bamboo fibre, polyvinyl chloride based products require a report, statistical returns, original records and the basis of the calculation, while polyolefin based products require a report, statistical returns and original records together with testing in accordance with LY/T 2554 and the test report. The packaging of the product requires evidence of the packaging marking and a self-declaration by the enterprise. The comprehensive energy consumption per unit of product is calculated in accordance with GB/T 2589, with energy use records and production records provided. Whether a dust recovery installation is fitted, and whether a wastewater treatment installation is present, both require evidence of the purchase of the equipment and records of its use and maintenance. The particulates in the production shop are tested in accordance with GBZ/T 192.1 and the noise in accordance with GBZ/T 189.8, with the test reports provided. The harmful substances in the product packaging are tested, after microwave digestion of the sample in a high-pressure system, in accordance with GB/T 15337 or GB/T 37837, GB/T 15337 governing in the event of arbitration, with the test report provided. Lead salt stabilizers require the raw material list and a self-declaration by the enterprise. Phthalates are tested in accordance with GB/T 22048. Flame retardants require the list of raw materials used and testing in accordance with GB/T 26125. Formaldehyde emission is tested in accordance with GB 18580 and volatile organic compounds in accordance with GB/T 29899. The migration limits for harmful elements are tested in accordance with GB 6675.4-2014. The ageing resistance of the product is tested, for outdoor wood-plastic products, by the xenon arc weathering method of GB/T 29365-2012, and for indoor wood-plastic products in accordance with 4.31 of GB/T 17657-2022. The mould resistance is tested in accordance with GB/T 35469-2017, and its durability by testing in accordance with GB/T 35469-2017 after 1000 h of xenon arc ageing to GB/T 29365. The resistance to boiling water is tested in accordance with A.3. The service life of the product requires the instructions for use, the certificate of conformity, the contract with the customer or a self-declaration by the enterprise. The product carbon footprint report is drawn up with reference to Annex B and provided as a report.

The notes to Table 1 are legible. A dash in the unit column means that the indicator has no unit symbol. Footnote a: for outdoor wood-plastic products the ageing time is 6000 h and for indoor wood-plastic products 4000 h. Footnote b: for outdoor wood-plastic products the ageing time is 5000 h and for indoor wood-plastic products 3000 h. Footnote c: only outdoor wood-plastic products are tested.

5 Assessment method

A product that meets both the basic requirements and the green benchmark product values of the assessment indicators is judged to be a green benchmark wood-plastic product; a product that meets both the basic requirements and the green product values of the assessment indicators is judged to be a green wood-plastic product.

Annex A Annex A (normative) Calculation of the indicators and test methods

A.1 Addition rate of recycled raw materials. The rate is calculated by formula (A.1) as the quantity of recycled raw material — recycled plastic and natural fibre material — added to the wood-plastic products within one year, in tonnes, divided by the total quantity of the main raw materials over the same year, in tonnes, multiplied by 100. The result is a percentage.

A.2 Recovery and utilization rate of waste wood-plastic products. The rate of recovery and use of wood-plastic products after they have been removed and discarded is calculated on the basis of the mass recovered per tonne of wood-plastic product discarded, by formula (A.2): the total mass that can be used after recovery, in tonnes, divided by the total mass recovered, in tonnes, multiplied by 100. The result is a percentage.

A.3 Resistance to boiling water. Three test pieces, each 100 mm +/- 1 mm long, not less than 50 mm wide and of the thickness of the sample, are fixed in a vessel holding boiling distilled water. During the test the pieces are not to touch one another and the liquid level is to stay not less than 10 mm above them. After boiling for 120 h +/- 0.5 h the pieces are taken out, the surface water is wiped off with filter paper, and after cooling to room temperature the pieces are examined in daylight for cracking, delamination and blistering. Where none of the three pieces shows cracking, delamination or blistering, the result is judged to conform.

Annex B Annex B (informative) Example of a carbon footprint report for wood-plastic products

B.1 Basic information. Table B.1 gives the basic information table of the carbon footprint report, with entries for the name and address of the producing enterprise, its unified social credit code, the contact person and telephone number, the product name and model, the product standard, the functional unit, the system boundary, the data collection period and the assessment result, together with the report date and the signature lines for approval, review and preparation. The example is filled in with placeholder characters for the enterprise details, and states that the carbon footprint of one tonne of outdoor wood-plastic profile of the 60 model was assessed in accordance with Clause 6 of ISO 14067:2018, the functional unit being one tonne of that profile from resource extraction, the production of raw and auxiliary materials and their transport, and energy production, through product manufacture to the works gate, that is from cradle to gate. The result table lists the life cycle stages — the production and transport of the raw and auxiliary materials, energy production and product manufacture — with the carbon footprint in kilograms of carbon dioxide equivalent and the contribution in percent, the figures being left as placeholders and only the total contribution of 100.00 percent printed. Three placeholder lines are left for the recommendations for reducing carbon emissions.

B.2 Purpose. By quantifying the greenhouse gas emissions over the life cycle of the wood-plastic products, the potential contribution of the products made by the enterprise to global warming is calculated, expressed as carbon dioxide equivalent.

B.3 System boundary. The life cycle system boundary of the product defined in the report is shown in Figure B.1 and takes in the production of raw and auxiliary materials, such as high density polyethylene, additives and masterbatch; energy production, such as electricity; transport, being the transport of the main raw materials; and the manufacture of the wood-plastic products.

B.4 Data collection. The data collected take in the energy consumption, the raw material consumption, the waste discharged and the transport distances of the production process, given in Tables B.2 to B.4, together with the upstream background data, being the inventory data for the extraction of raw materials, the production of energy and the transport of the raw and auxiliary materials, given in Table B.5. Table B.2, the energy consumption data, gives electricity as 800 kW h. Table B.3, the raw material consumption data, lists high density polyethylene, wood fibre, antioxidant, ultraviolet absorber, compatibilizer, flame retardant masterbatch, colour masterbatch, lubricant, mould inhibitor and water, each with its quantity in tonnes, its mode of transport, given as road haulage except for water which is piped, and its transport distance in kilometres; a note records that the transport distance of the water is not counted. The name of the flame retardant masterbatch is printed as reset flame retardant masterbatch in Table B.3 and as compound flame retardant masterbatch in Table B.5. Table B.4, the waste discharge data, lists high density polyethylene, wood fibre and packaging material with their quantities left as placeholders. Table B.5 lists the same materials together with electricity and transport, all produced in China, with the sources of the emission factors left as placeholders.

B.5 Rules for data cut-off and allocation. Where the different kinds of data of several unit processes fall within the life cycle system boundary of the product, the data are to be cut off suitably on the following principles: all energy inputs are listed; all raw material inputs are listed; all greenhouse gas emissions are listed; and material and energy flows whose contribution in the inventory analysis is below 1 percent may be disregarded. The allocation principle is that the material and energy input for the production of the outdoor wood-plastic profile of the 60 model is the product of the material and energy input of the whole plant for that series of profiles and the share, in the total input to that series across all its models and quantities, of the quantity produced of the 60 model.

B.6 Calculation method. The product carbon footprint is calculated by formula (B.1) as the sum, over the activities, of the product of the activity data, the emission factor and the global warming potential. The activity data are the data on the greenhouse gas emissions and removals of the i-th activity within the system boundary for each functional or declared unit, including primary and secondary data, in units fixed by the emission source concerned. The emission factor is the greenhouse gas emission factor corresponding to the i-th activity, in units matching those of the activity data. The global warming potential is the value corresponding to the i-th activity, which may be taken from the data given in the assessment reports of the Intergovernmental Panel on Climate Change; where those values are revised by the Panel, the latest values are to be used in the calculation of the product carbon footprint.

B.7 Calculation result. The life cycle carbon footprint impact assessment result of the product is given in Table B.6, which lists the impact category as the carbon footprint, that is the global warming potential, with the unit kilograms of carbon dioxide equivalent and the quantity left as a placeholder.