GB/T 42996.2-2023Guidelines for the control of key chemical substances in furniture—Part 2: Upholstered furniture (English PDF)

3.2 Key volatile organic compounds

Volatile organic compounds in furniture that have been proven or confirmed to be toxic to the human body and the environment and need to be strictly controlled.

6.2 Instruments and equipment

6.2.1 Climate chamber. should comply with the requirements of GB/T 31107.

6.2.2 Constant flow gas sampler. The flow rate is stable and adjustable within 0mL/min~1000mL/min, and the accuracy is within ±5%.

6.2.3 Gas chromatograph. equipped with hydrogen flame detector (GC/FID) or mass selective detector (GC/MSD).

6.2.4 Thermal desorption device. should comply with the requirements of 5.3.10 and 5.3.11 in GB/T 31106-2014.

6.2.5 High performance liquid chromatography (HPLC). equipped with diode array or UV detector.

6.3 Storage of samples before testing

Upholstered furniture easily absorbs chemicals in the ambient air. The storage conditions before testing are one of the important factors affecting the results. In order to reduce environmental pollution, To avoid interference caused by the environment, samples should be stored in the original sealed state in an indoor environment to avoid contact with chemical pollutants, and the storage environment should be controlled.

The concentration of key chemical substances in the environment is lower than the recommended value for control.

The storage temperature is 15°C~25°C, and the relative humidity is not higher than 65%. Unpackaged samples are taken to avoid cross-contamination.

6.4 Test procedure

6.4.1 Loading factor and climate chamber selection

Try to choose a climate chamber with a load-bearing rate calculation result of 0.30m²/m3~0.70m²/m3, and try to be as close as possible to 0.50m²/m3.Small Samples should be added to meet the load-carrying rate range by increasing the number of identical samples.

Products with evenly distributed materials should be tested as a whole or the samples should be prepared into specimens with a load-bearing rate of 0.50m²/m3, using 1m³ of air. Waiting room test.

6.4.2 Sample preparation

6.4.2.1 Sample processing

Remove the packaging, protective film, hang tag and other packaging materials of the sample (if the product requires assembly, install the product according to the installation requirements specified by the product) product), use a dry cotton cloth to clean the surface dust. Products with particularly large samples and evenly distributed materials should be prepared into specimens for testing according to 6.4.2.3. The results are as follows.

In case of dispute, the test results of the entire sample shall prevail. For products with uneven material distribution, the entire sample should be tested.

6.4.2.2 Measure the exposed area of the sample

Close the movable structure of the sample, unfold it for daily use, and measure and calculate the exposed area of the sample according to Appendix A.

6.4.2.3 Specimen preparation

If you need to prepare small sample specimens, you need to take proportional samples, including the main release sources of the sample. In order to ensure that the results of small test pieces and whole samples are consistent Consistent, try to avoid edge areas as much as possible, select a position more than 100mm from the edge of the sample, and include all materials as much as possible, from fabric to elastic filling.

Sampling of the entire filling material. All incisions of the small test piece and the unexposed parts of the original product are sealed with aluminum tape that does not contain the key chemicals being tested.

Seal, or place the sample on a stainless steel plate and seal the sides with aluminum tape. When sealing the side, cover it to the surface (10±5)mm. Front and back materials For different products with a main material ratio of 1.1, samples are taken from the front and back, and sealed back-to-back to prepare small test pieces.

6.4.3 Preprocessing

Samples should be placed in a pretreatment environment as soon as possible after preparation. When multiple samples are preprocessed at the same time, the distance between samples should be greater than 300mm as much as possible to ensure Maintain air circulation to avoid sample cross-contamination. The preprocessing process needs to meet the following conditions.

---Pretreatment environmental conditions. temperature is (23±2)°C, relative humidity is (50±10)%;

---Pretreatment time. (120±2)h.

6.4.4 Preparation of climate chamber

Clean the inner wall of the climate chamber with alkaline detergent, then clean it with distilled water and ventilate and dry it.

Open the climate chamber, adjust the temperature inside the chamber to (23±2.0)°C, the relative humidity to (50±5)%, the air exchange rate (1.0±0.05)h-1, and the air After running for 24 hours, the air in the cabin was collected and the background concentration of the key chemical substances listed in Table 1 was tested.

6.4.5 Sample testing

After the sample pretreatment is completed, it is immediately transferred to the climate chamber for testing. Mattress samples should be placed on the stand, and other products should be in normal use.

Place it in the middle of the cabin. The bracket should be made of materials that are not easy to adsorb or release the key chemical substances in Table 1, and should occupy less space than the cabin.

1% of the volume to avoid affecting the air circulation in the cabin.

Close the hatch and record the time, start collecting the air in the cabin for measurement at (20±0.5) h, and calculate the key chemical values under the test conditions.

Substance test concentration. Before collecting the air in the cabin, it is recommended to extract the air in the cabin without the adsorption tube for at least 5 minutes to remove the leakage in the sampling pipe. interference. The sampling flow rate should not exceed 80% of the air flow rate at the inlet of the environmental chamber.

During the test, the environmental indicators in the climate chamber should be kept constant.

---Temperature. (23±2.0)°C;

--- Relative humidity. (50±5)%;

---Air exchange rate. (1.0±0.05)h-1.

6.5 Collection and determination of key chemical substances

Formaldehyde, acetaldehyde and acrolein should be collected and measured according to the methods specified in ISO 16000-3:2011, and benzene, toluene and xylene should be collected and measured according to the methods specified in ISO 16000-3:2011.

Collect and measure according to the methods specified in GB/T 31106-2014 or ISO 16017-1:2000 and ISO 16000-6:2011, other key points Chemical substances should be collected and measured in accordance with the provisions of ISO 16017-1:2000 and ISO 16000-6:2011.See Appendix B for test conditions.

6.6 Result calculation

6.6.1 Test concentrations of key chemical substances under test conditions

The test concentration of key chemical substances under test conditions is calculated according to formula (1). Cv=Cvc-C0v (1) In the formula.

Cv ---The mass concentration of key chemical substances under test conditions, in milligrams per cubic meter (mg/m3);

Cvc ---The test results of the mass concentration of key chemical substances in the climate chamber, in milligrams per cubic meter (mg/m3);

C0v ---The test results of the mass concentration of key chemical substances in the background of the climate chamber, in milligrams per cubic meter (mg/m3).

6.6.2 Release amounts of key chemical substances in samples

The release amount of key chemical substances in the sample is calculated according to formula (2). L×Cv (2) In the formula.

C ---The release amount of key chemical substances in the sample, in milligrams per cubic meter (mg/m3);

L ---Loading rate of the sample, unit is square meter per cubic meter (m2/m3);

L0 --- standard load-bearing rate, the value is 0.5, the unit is square meters per cubic meter (m2/m3).

6.7 Result presentation

The release amount of key chemical substances in upholstered furniture is expressed in mg/m3, and the results are consistent with the number of digits of the control recommended values in Table 1.