- 1 - ICS 87.040 
G 51 
 
 
 
 
National Standard  
of the People's Republic of China 
 
 
GB18581-XXXX 
 Replaces GB 18581-2001 
 
 
Indoor decorating and refurbishing materials – limit of harmful substances of 
solvent coatings for woodenware 
 
  
  
Draft for approval 
 
 
 
       Issue Date: XXXX – XX – XX Im plementation Date: XXXX – XX – XX 
 
 
  
Issued by the General Administration of Qual ity Supervision, Inspection and Quarantine of 
the People's Republic of China  
 
Standardisation Administration of th e People's Republic of China (SAC) 
- 2 -  
 
Foreword 
 
 This Standard replaces GB 18581- 2001, “Indoor decorating and refu rbishing materials – limit of 
harmful substances of solven t coatings for woodenware”.  
 The main technical differences between this Standard when compared to GB 18581-2001 are: 
− the applicable range of this Standard are pol yurethane-based, nitroce llulose-based, alkyd-based 
solvent coatings (including top co ats and base coats) and all type s of solvent-based putties for 
woodenware used for indoor and f actory decorating and refurbishing; 
− the addition of all types of solvent-based putties in the applicable range and their prescribed 
harmful substances limit; 
− the clarified applicable range does not apply to irradiati on curable coatings; 
− the addition of the content limit requirement of methanol in nitrocellulose coatings; 
− the total limit requirement of methylbenzene and xylene clearly clarified as the total limit 
requirement of methylben zene, xylene and ethylene; 
− the alteration of the content limit requirement of free diisocyanate to the total content limit 
requirement of free diisocyanate (TDI + HDI); 
− the addition of the content limit requirement of halohydrocarbon; 
− in all types of coatings, the limit values of total of the vo latile organic compound (VOC), 
benzene, methylbenzene, xylene, and ethylbenzene,  as well as free diisocyanate (TDI+HDI) are 
more strictly limited; 
− the addition of the definition of volatile organi c compound (VOC) and its content, specified the 
corresponding test method; 
− specification of the test methods for methanol and halo-hydrocarbon; 
− the modification and perfection of the test me thod for total of benzene, methylbenzene, 
ethylbenzene and xylene; 
− the test method for soluble heavy meta ls has been modified and perfected. 
 Appendix A, Appendix B, and Appendix C to this Standard are normative annexes.  This Standard is proposed by the China Petrol eum and Chemical Industr y Association (CPCIA) 
 This Standard is under the jurisdiction of the National Technical Committee of Paint & Pigments for Standardisation  The organisation responsible fo r drafting this Standard:  
 The organisations that pa rticipated in the drafting of this Standard:  
 The main drafters of this Standard: 
 
This Standard was first issued on 10 December 2001. This is the first revision of this Standard. 
 The National Technical Committee of Paint & Pigmen ts for Standardisation is entrusted for the 
interpretation of this Standard.  - 3 -  
          
Indoor decorating and refurbishing materials –  
limit of harmful substances of solvent coatings for woodenware 
 
1 Scope 
This Standard specifies the a llowable limit requirements, the test methods, inspection rules, 
packaging symbols, painting safe ty and protection methods of s ubstances which are harmful to 
human health and the environment contained in pol yurethane based, nitrocellulose based and alkyd-
based solvent coatings and all t ypes of solvent-based putties for indoor decorating and refurbishing. 
 This Standard applies to polyuret hane based, nitrocellulose based and alkyd-based solvent coatings, 
as well as all types of solvent-based putties for indoor and factory woodenware decorating and 
refurbishing. This Standard does not a pply to irradiation curable coating. 
2 Normative References 
The provisions of the following documents become  provisions of this Standard after being 
referenced. For dated reference documents, a ll later amendments (excluding corrigenda) and 
versions do not apply to this Standard; however, the parties to the agreem ent are encouraged to 
study whether the latest versions of these doc uments are applicable. For undated reference 
documents, the latest versions apply to this Standard.  GB/T601 Chemical reagent – Preparations of standard volumetric solutions  GB/T1250 Expression methods and determ ination methods for limit values 
 GB/T1725 Paints, varnishes and plastics – Dete rmination of non-volatile  matter content (GB/T 
1725-2007, ISO 3251:2003, IDT) 
 GB/T3186 Paints, varnishes and ra w materials for paints and va rnishes – Sampling (GB/T 3186-
2006, ISO 15528:2000, IDT)  GB/T6682 Water for analytical laboratory use – Specification and test methods (GB/T6682-1992 
neq ISO3696:1987)  GB/T6750 Paints and varnishes – Determination of density – Part 1:  Pyknometer method 
(GB/T6750-2007, ISO 2811-1:1997, IDT)  GB/T9750 Marks for packag e of coating products 
 GB/T9754 Paints and varnishes – Measurement of specular gloss of non-meta llic paint films at 20
o, 
60o and 85o 
 GB/T18446 Binders for paints and varnishes – De termination of monome ric diisocyanates in 
polyisocyanate resins  GB18582 Indoor decorating and refurbishing materials – Limit of harmful substances of paints for 
interior wall  - 4 - 3 Terms and definitions 
The terms and definitions listed below apply to this Standard. 
3.1 Volatile organic compound (VOC) 
Any organic compound which, under the standard pre ssure of 101.3Kpa, has an  initial boiling point 
equal to or below 250oC, shall be considered a volatile organic compound. 
3.2 Volatile organic compound content 
The content value of volatile organic compounds m easured in accordance with prescribed test 
methods to test the product.  
Note 1: the content value of volatile organic compound for all types of coatings and all types 
of putties shall be represented by gram per litre (g/L). 
3.3 Polyurethane coatings 
Type of coating with polyurethane resin as the main film forming matter, where the polyurethane 
resin is generated by the reactions between pol yisocyanate and the compound contains active 
hydrogen. 
3.4 Nitrocellulose coatings 
Type of coating with cellulose nitr ate as the main film forming matte r, where the cellulose nitrate is 
generated by the reactions betwee n cellulose esterification and the mixture of nitric acid and 
sulphuric acid.  
3.5 Alkyd coatings 
Type of coating with alkyd resin as the main film forming matter, where the alkyd resin is prepared 
by the polycondensation of polybasic acid, fatty  acid (or vegetable oil) and polyols. 
4 Requirements 
The limit of the harmful substances  contained in products must conf orm to the requirements set out 
in Table 1: 
Table 1 Limit requirements of harmful substances 
Limit Value 
Polyurethane coatings Item 
Top coat Base coat Nitrocellulo
se coatingsAlkyd  
coatings Putty 
 
V olatile organic 
compounds (VOC)a Gloss (60o) 
≥ 80, 
≤580 (g/L) 
Gloss (60o) 
< 80, ≤670 
(g/L) ≤ 670 (g/L) ≤ 720 (g/L) ≤ 500 
(g/L) ≤ 550 (g/L)
Benzene  ≤ 0.3 - 5 - (Total of Methylbenzene, 
Xylene and Ethylbenzene)
a/%  ≤ 30 ≤ 30 ≤ 5 ≤ 30 
Total free diisocyanate 
(TDI+HDI)b/% ≤ 0.4 - - - 
Methanola/% - ≤ 0.3 - ≤ 0.3 
(limited to 
nitrocellulo
se putty) 
 
Halohydrocarbon a,c/% ≤ 0.1 
Soluble lead ≤ 90 
Soluble 
cadmium ≤ 75 
Soluble 
chromium ≤ 60 Heavy 
metal (limited to coloured paint and putty)/(mg/kg) Soluble 
mercury ≤ 60 
a shall be determined after being blended in accordance with the specified proportions and 
the dilution rate of the product. If the amount  of the dilution solvents used is within a 
certain range, the total shall be determined after being diluted in accordance with the 
recommended maximum dilution quantity . 
b if polyurethane coatings specifie d the dilution rate or when formed by two components or 
multi components, the content of firming age nts (contain free diisocyanate prepolymer) 
shall be determined first, then  the contents in the blended coating shall be calculated in 
accordance with the specified proportion of th e product. If the amount of dilution solvent 
used is within a certain range , the contents shall be determined in accordance with the 
recommended minimum dilution quantity. 
c including dichloromethane, dichloroethane (1,1- dichloroethane, 1, 2 dichloroethane), 
trichloromethane (1,1,1 trichloromethane , 1, 1,2 trichloromethane ), trichloroethane, 
carbon tetrachloride . 
 
5 Test methods 
5.1 Sampling 
Product sampling shall be performed in accordan ce with the provisions specified in GB/T3186. 
5.2 Test methods 
5.2.1 The volatile organic compounds (VOC) test sh all be performed in accordance with the 
provisions set out in Appe ndix A to this Standard. 
 5.2.2 The methanol, benzene, methylbenzene, ethylbe nzene and xylene tests shall be performed in 
accordance with the provisions set out in Appendix B to this Standard. - 6 -  
5.2.3 The content test of free diisocyanate (TDI+ HDI) shall be conducted in accordance with the 
provisions specified in GB/T18446-XXXX.  5.2.4 The content test of halohydrocarbon shall be  conducted in accordance with the provisions 
specified in Appendix C.  5.2.5 The content test of soluble heavy metals (lead, cadmium, ch romium and mercury) shall be 
conducted in accordance with the provisions specified in GB 18582. 
6 Inspection rules 
6.1 The entire requirements list ed in this Standard are insp ection items for type approval. 
 6.1.1 Under normal production conditions, the inspecti on for type approval shall be conducted at 
least once per year.  6.1.2 Under any of the following conditions, the insp ection for type approval shall be conducted at 
any time: 
- first finalisation of a newly designed product; - if the place of production of the product is changed; 
-  if major changes are made to the dispensa tion formula, technology, the main source of raw 
materials and the product construction proportion; - if production is stopped for three months then re-started again. 
6.2 Determination of inspection results 
6.2.1 The determination of the in spection results shall be conduc ted in accordance with the 
comparison method using round off values as specified in GB/T1250.  
6.2.2 The inspection result statement shall clearly indicate the proportion s of the components. 
 6.2.3 When the inspection resu lts of all items have met the require ments of this Standard, then the 
product can be considered as in conformance with this Standard. 
7 Packaging symbols 
7.1 In addition to complying with the provision s specified in GB/T9750, the product packaging 
symbol must also clearly state that the product meet s the inspection qualificat ions of this Standard. 
 7.2 For coatings which are set-formed by two co mponents or multi-components, the proportion of 
each component must be clearly indicated on the p ackaging symbol. For coatings which need to be 
diluted when carrying out construction, the diluti on proportion must be indi cated on the packaging 
symbol. 
8 Painting safety and protection 
8.1 The room must be well ventilated when painting. 
 8.2 Construction personnel must wear the n ecessary protective clothing when painting. 
 8.3 Interior ventilation must be continuously maintained after painting is completed. 
 - 7 - Appendix A 
(Normative Annex) 
Content Determination of Vola tile Organic Compound (VOC) 
 
A.1 Theory 
The sample shall be tested using the gas chro matography method. If an y organic compound with a 
boiling point greater than 250o C is not detected in the sample, then the tested volatile value shall be 
the VOC content of the product; if any organic compound with a boiling point greater than 250oC is 
detected in the sample, then the qualitative determination and quantitative analysis shall be conducted on the detected organic compound in the sample which has a boili ng point greater than 
250
oC. The difference value in deducting the compound content (V paint) with a boiling point greater 
than 250oC from the volatile (V) shall be the VOC content of the product. 
A.2 Materials and reagents 
A.2.1  Carrier gas: nitrogen, pur ity must be at least 99.995%; 
A.2.2  Combustion gas: hydrogen, purity must be at least 99.995%;  
A.2.3  Combustion-supporting gas: air; 
A.2.4  Assisting gas (septum purge and make-up gas): nitrogen which has the same properties as the 
carrier gas; 
A.2.5  Internal standard: the compound which is not  contained in the sample, which can be 
completely separated from other components on th e chromatogram. The purity of the internal 
standard must be at least 99% (mass fraction) or a prescribed purity. For example: dimethyl 
phthalate, diethyl phthalate etc. 
A.2.6  Calibration compound: The compound used for correction must be at least 99% (mass 
fraction) or a prescribed purity. 
A.2.7  Dilution solvent: the organic solvent used for diluting the sample must not contain any 
substances that are able to influence the tests. The purity of the dilution solvent must be at least 
99% (mass fraction) or a prescribed purity. 
A.2.8  Marker: the compound used to divide th e VOC component and non-VOC component in 
accordance with the VOC definition. In this Standar d, the marker is specified as diethyl adipate 
(boiling point is 251oC). 
A.3 Instruments and facilities 
A.3.1  Gas chromatograph, equipped with the following devices 
A.3.1.1  Sample injection port of the split injector, the liner of the vaporisation chamber is 
replaceable; 
A.3.1.2  Programmed temperature controller; 
A.3.1.3  Detector; 
Any one of the three detectors listed below can be selected: 
A.3.1.3.1  Flame Ionisation Detector (FID); 
A.3.1.3.2  A corrected and tuned mass spectroscopy or any other mass selective detector; 
A.3.1.3.3  A corrected Fourier Transform Infrared Sp ectrometer (FT-IR optical spectrometer). - 8 - Note: if any of the detectors mentioned in  A.3.1.3.2 and A.3.1.3.3 are selected to conduct the 
qualitative determination of the organic co mpounds with a boiling point greater than 250oC, then 
the detector must be connected to the gas ch romatograph and operated in accordance with the 
relevant instructions specified by the detector manufacturer. 
A.3.1.4  Chromatography column: polydimethylsiloxane capillary column; 
A.3.2  Sample Injection Device: microinjector, 10µl; 
A.3.3  Sample Preparation Bottle: a glass bottle with a capacity of appropriately 10ml, air-tight lid; 
A.3.4  Scales: precision to 0.1mg. 
A.4 Test conditions of gas chromatography 
Chromatographic column: polydimethylsiloxane  capillary column, 30m x 0.25mm x 0.25µm or 
other equivalent types; 
Temperature of the sample injection port: 300oC; 
Detector: FID, temperature: 300oC; 
Column temperature: the init ial temperature must be 160oC and maintained for 1 minute; the 
temperature is then increased by increments of 10oC per minute until it reaches 290oC, maintaining 
this temperature for 15 minutes; 
Flow rate of the carrier gas: 1.2ml per minute; Split ratio: sample split-injected, adjustable split ratio; Sample size: 1.0µl Note: the test conditions of the gas chromat ography can be selected on the basis of the 
characteristics of the devices used and th e actual conditions of the test sample. 
A.5 Test procedures 
A.5.1 Density 
Mix together all the prescribed sample component s in accordance with the proportion rate specified 
in the product instructions, stir until well mixed, and then determine the density ( ρ) of the sample in 
accordance with the provisions specified in GB /T 6750. The test temperature must be 23± 2
oC. 
A.5.2  The gloss measurement of the polyurethane coat ings must be conducted in accordance with 
the provisions specified in GB /T9754. After mixing the main agen t, the firming agent and the 
dilution solvent together in accordance with the pr oportion rate specified in the product instructions, 
use a wet film applicator with a slot depth of  (100± 2)µm to produce a sample board. After the 
sample board is dry, use a specular gloss meter of 60o to obtain measurements. 
A.5.3 Volatile matter (V) 
Mix all the prescribed sample components in accor dance with the proportion rate specified in the 
product instructions, stir until well mixed, then determine the volatile matter(V) content of the 
sample in accordance with the provisions specif ied in GB/T 1725. Test conditions shall be (105± 
2)oC/3h. 
A.5.4 Volatile Organic Compound (VOC) 
A.5.4.1 The determination of the VOC content wh en the sample does not contain organic 
compounds with a boiling point greater than 250oC. 
If, after the qualitative anal ysis specified in A.5.4.2.2, no organic compound with a boiling point 
greater than 250oC is detected in the sample, then the VOC content in the sample shall be - 9 - determined by formula (A.1). 
 
Where:  VOC – the VOC content in the sample. Unit of  measurement is grams per litre (g/L); 
V – the mass fraction of the volatile matter in the sample; ρ – the density of the sample when the temperature is (23± 2)
oC. Unit of measurement is grams per 
millilitre (g/ml); 
1000 – the conversion factor. A.5.4.2  The determination of the VOC content when the sample containing organic compound 
which has a boiling po int greater than 250
oC 
A.5.4.2.1  Optimisation of chromatographic parameters 
According to the test conditions  of chromatography specified in  A.4, prescribed calibration 
compounds must be used to carry out optimised treatment, in order to maintain the optimum 
accuracy, stability and separation efficiency of the device. 
A.5.4.2.2.  Qualitative analysis 
Inject the marker into the gas chromatograph and measure its retention time on the 
polydimethylsiloxane capillary column in order to determine the integral starting point on the 
chromatogram in accordance with th e VOC definition specified in 3.1. 
Mix the prescribed sample com ponents in accordance with the pr oportion rate spec ified in the 
product instructions, stir until well mixed, then inject the sample in to the gas chromatograph, record 
the chromatogram, and carry out qualitative dete rmination for each compound with a retention time 
longer than the marker. The prefe rred selective method is to join tly use gas chromatography, the 
mass selective detector (A.3.1.3.2) or the FT-IR infr ared optical spectromet er (A.3.1.3.3), and to use 
the test conditions of gas chromatography specified in A.4. 
A.5.4.2.3  Calibration 
A.5.4.2.3.1  If the compound suitable for calibration is available for purchase, then the relative 
correction factor shall be dete rmined by the following methods. 
A.5.4.2.3.1.1  Preparation of the calibration sample: wei gh out a certain amount (precise to 0.1mg) 
of each calibration compound approved in A.5.4.2.2 a nd place into the sample preparation bottle 
(A.3.3). The weighted mass and the content of each compound in the test sample shall be of the 
same order of magnitude. Then weigh out the inte rnal standard (A.2.5) which has the same mass as 
the test compounds, and put into the same sample preparation bottle, use an appropriate dilution 
solvent (A.2.7) to dilute the mixture, seal up th e bottle and shake until the dilution is well mixed. 
A.5.4.2.3.1.2  Determination of the relative correction f actor: under the same test conditions of gas 
chromatography of the test sample, optimisation of  the chromatographic parameters in accordance 
with A.5.4.2.1. Inject a suitable amount of calibra tion compound into the gas chromatograph and 
record the chromatogram. The relative correction factor of each compound shall be determined by 
formula (A.2) respectively: 
 
- 10 - Where: 
 Ri – the relative correction factor of the compound i; 
mci – the mass of the compound in the calibration mixture. Unit of  measurement is grams (g); 
mis – the mass of the internal standard in the calibr ation mixture. Unit of measurement is grams (g); 
Ais – the peak area of the internal standard; 
Aci – the peak area of the compound i. 
Parallel test twice, take the mean va lue of the two test results as the R i value. Its relative deviation 
must be less than 5%; retain three significant numbers. 
A.5.4.2.3.2  In the case of a chromatographic peak whic h fails the qualitative determination, or the 
organic compound used for calibration failed the co mmercialisation, then the relative correction 
factor is assumed to be 1.0. 
A.5.4.2.4 Sample tests 
A.5.4.2.4.1  Sample preparation: accordi ng to the product inst ructions, blend all prescribed sample 
components; stir until the mixture is well mixe d. Weigh out 2g (precise to 0.1mg) of the well 
blended mixture, and weigh out th e internal standard (A.2.5) which has the same mass as the test 
sample, put them into the sample preparation bottle (A.3.3), add a suita ble amount of dilution 
solvent (A.2.7) (use injectable sample) into the same  bottle to dilute the samp le, seal the bottle and 
shake until the dilution is well mixed. 
A.5.4.2.4.2  According to the optimisation conditions during calibration time to set the device 
parameters. 
A.5.4.2.4.3  Inject the marker (A.2.8) into the gas chro matograph and record its  retention time on the 
polydimethylsiloxane capillary column in order to determine the integral starting point on the 
chromatogram in accordance with th e VOC definition specified in 3.1. 
A.5.4.2.4.4  Inject the 1.0µl sample prepared in A .5.4.2.4.1 into the gas chromatograph, record the 
chromatogram, and record the peak area of ever y compound with a retention time longer than the 
marker, then determine the mass fraction of each compound where its boiling point is greater than 
250oC respectively. 
Vpainti=mis×Ai×Ri
ms×Ais.......................................................(A.3) 
Where: 
Vpaint i – the mass fraction of compound i which is cont ained in the sample and its boiling point is 
greater than 250oC. Unit of measurement is gram per gram (g/g); 
Ri – the relative correctio n factor of compound i; 
mis – the mass of the internal standard. Unit of measurement is grams (g); 
ms – the mass of the sample. Unit of measurement is grams (g); 
Ai – the peak area of compound i; 
Ais – the peak area of the internal standard. 
- 11 - Parallel test twice, the mean value from the two test results shall be regarded as the V paint i value. 
A.5.4.2.4.5 The content of the compound which is contained in the sample with a boiling point is 
greater than 250oC shall be determined by the formula (A.4). 
Vpaint=∑
i=1n
Vpainti.................................................(A.4) 
where: 
Vpaint – the mass fraction of th e compound which is contained in th e sample and has a boiling point 
is greater than 250oC. 
A.5.4.2.5  The content of the compound which is containe d in the sample and has a boiling point is 
equal to or less than 250oC, shall be determined by the formula (A.5). 
VOC =V−Vpaint× × 1000...................................(A.5) 
Where: 
VOC - the content of the compound which is contai ned in the sample and its boiling point is equal 
or less than 250oC; 
V – the mass fraction of the volatile matte r which is contained in the sample; 
Vpaint – the mass fraction of the compound which is co ntained in the sample and has a boiling point 
is greater than 250oC. 
ρ – the density of the sample when  the temperature range is (23± 2)oC. Unit of measurement is 
grams per millilitre (g/ml); 
1000 – the conversion factor. 
A.6 Accuracy 
A.6.1 Repeatability 
Tests carried out by the same operator, in the sa me laboratory, using the same device, within a 
certain time interval, on the same sample should provi de a relative deviation in  the tested results of 
less than 5%. 
A.6.2 Reproducibility 
Tests carried out by different operators, in differen t laboratories, on the same sample should provide 
a relative deviation in the test ed results of less than 10%. - 12 - Appendix B 
(Normative Annex) 
Content Determination of methanol, benzene,  methylbenzene, ethylbenzene, and xylene 
B.1 Theory 
After the sample is diluted, inject  the dilution directly into the gas chromat ograph. After separation 
by the chromatographic column, test the sample with a hydrogen flame ionisation detector. Use the 
internal standard method to dete rmine the amount of the contents. 
B.2 Materials and reagents 
B.2.1  Carrier gas: nitrogen, pur ity must be at least 99.995%; 
B.2.2  Combustion gas: hydrogen, purity must be at least 99.995%; 
B.2.3  Combustion-supporting gas: air; 
B.2.4  Assisting gas (septum purge and make-up gas) : nitrogen with the same properties as the 
carrier gas; 
B.2.5  Internal standard: the compound which is not contained in the sample, which can be 
completely separated from other components on th e chromatogram. The purity of the internal 
standard must be at least 99% (mass fraction) or a prescribed purity. For example: n-heptane, and n-
pentane etc,. 
B.2.6  Calibration compound: methanol, benzene, met hylbenzene, ethylbenzene and xylene, their 
purity must be at least 99% (mass fraction) or a prescribed purity. 
B.2.7  Dilution solvent: the organic solvent used for diluting the sample, must not contain any 
substances that are able to influence the tests. The purity of the dilution solvent must be at least 
99% (mass fraction) or a prescribed purity. For example: ethyl acetate, n-hexane etc. 
B.3 Instruments and facilities 
B.3.1  Gas chromatograph, equipped with the following devices 
B.3.1.1  Sample injection port of the split injector, the liner of the vaporisation chamber is 
replaceable; 
B.3.1.2  Programmed temperature controller; 
B.3.1.3  Detector: Flame Ionisation Detector (FID); 
B.3.1.4 Chromatographic column: must enable the test  substances to be co mpletely separated from 
other components, such as a polydimethylsiloxane  capillary column, 6% cyano-propylphenyl /94% 
polydimethylsiloxane capillary column, polyethylen e glycol capillary column or other equivalent 
types;  B.3.2  Sample Injection Device: microinjector, 10µl; 
B.3.3  Sample Preparation Bottle: a glass bottle with a capacity of appropriately 10ml, air-tight lid; 
B.3.4  Scales: precise to 0.1mg. 
B.4 Test conditions of gas chromatography 
Chromatographycolumn: polydimethylsiloxane capi llary column, 30m x 0.25 mm x 0.25µm or other 
equivalent types; 
Temperature of the sample injection port: 240
oC; - 13 - Detector temperature: 280oC; 
Column temperature: the initial temperature must be 50oC and maintained for 5 minutes, after 
which the temperature should be increased by increments of 10oC per minute until it reaches 280oC, 
maintaining this temperature for 15 minutes; 
Pre-column pressure: 35kPa; Split ratio: sample split-injected, adjustable split ratio; Sample size: 1.0µl Note: the test conditions of the gas chromat ography can be selected on the basis of the 
characteristics of the devices used and th e actual conditions of the test sample. 
B.5 Test procedures 
B.5.1 Optimisation of chro matographic parameters 
According to the test conditions  of chromatography specified in  B.4, prescribed calibration 
compounds must be used to carry out optimised treatment, in order to maintain the optimum 
accuracy, stability and separation efficiency of the device. 
B.5.2 Calibration 
B.5.2.1  Preparation of the calibration sample: weigh out  a certain amount (preci se to 0.1mg) of each 
calibration compound approved in B.2.6 and place into  the sample preparation bottle (B.3.3). The 
weighted mass and the content of each compound in th e test sample must be of the same order of 
magnitude. Then weigh out the internal standard  (B.2.5) which has the same mass as the test 
compounds, and put into the same sample preparat ion bottle. Use an appropriate dilution solvent 
(B.2.7) to dilute the mixture, seal up the bot tle and shake until the dilution is well mixed. 
B.5.2.2  Determination of the relative  correction factor: under the same test  conditions of gas 
chromatography of the test sample, optimisation of  the chromatographic parameters in accordance 
with B.5.1. Inject a suitable amount  of calibration compound into th e gas chromatograph and record 
the chromatogram. The relative correction fact or of each compound shall be determined by the 
formula (A.2) respectively: 
Where: 
R
i – the relative correction factor  of methanol, benzene, methyl benzene, ethylbenene, and xylene 
respectively corresponding to  the internal standard; 
mci – the individual mass of metha nol, benzene, methylbenzene, ethylbenene, and xylene in the 
calibration mixture. Unit of measurement is grams (g); 
mis – the mass of the internal standard in the calibr ation mixture. Unit of measurement is grams (g); 
Ais – the peak area of the internal standard; 
Aci – the peak area of methanol, benzene, me thylbenzene, ethylbenzene, and xylene in the 
calibration mixture. 
Parallel test twice, take the mean va lue of the two test results as the R i value. Its relative deviation 
must be less than 5%; retain three significant numbers. 
 
- 14 - B.5.3 Sample test 
B.5.3.1  Sample preparation: according to the product instructions, blend al l prescribed sample 
components, stir until the mixture is well mixed. Weigh out 2g (precise to  0.1mg) of the well 
blended mixture, and weigh out the internal stan dard (B.2.5) which has the same mass as the test 
sample, put them into the sample preparation bottle (B.3.3), add a suitable amount of dilution 
solvent (B.2.7) (use injectable sample) into the sa me bottle to dilute the sample, seal the bottle and 
shake the bottle until th e dilution is well mixed. 
B.5.3.2  According to the optimisation conditions duri ng calibration time to set the device parameter. 
B.5.3.3  Inject 1.0µl sample which is prepared in B.5.3.1 into the gas chromatograph, record the 
chromatogram, the content of the test substances (methanol, benzene, methyl benzene, ethylbenzene, 
and xylene) contained in the sample sha ll be determined by the formula (B.2).  
Where: 
mI – the mass fraction of the test  component i in the sample; 
Ri – the relative correction factor of test component i; 
mis – the mass of the internal standard, unit of measurement is grams (g); 
ms – the mass of the sample, unit of measurement is grams (g); 
Ai – the peak area of the test component i; 
Ais – the peak area of the internal standard. 
Note: in the case that test subs tances are not be able to sepa rated effectively when under test 
conditions of gas chromatography specified in B.4, and therefore the determination can not be 
correctly deduced, then other type s of chromatography columns (see the list in B.3.1.4) or other test 
conditions of gas chromatographs used for the re placement shall be permitte d, to enable the test 
substances to be efficiently separated a nd the content determination can be deduced. 
Parallel test twice, take the mean value of the two test results as the content of the test substance. Its 
relative deviation must be less than 5%. 
B.6 Accuracy 
B.6.1 Repeatability 
Tests carried out by the same operator, in the sa me laboratory, using the same device, within a 
certain time interval, on the same sample should provi de a relative deviation in  the tested results of 
less than 5%. 
B.6.2 Reproducibility 
Tests carried out by different operators, in differen t laboratories, on the same sample should provide 
a relative deviation in the test ed results of less than 10%. 
- 15 - Appendix C 
(Normative Annex) 
Content Determination of halohydrocarbon 
 
C.1 Theory 
 
After the sample is diluted with dilution solven t, inject the dilution directly into the gas 
chromatograph, after the dichloromethane, dichloro ethane, trichloromethane, trichloroethane, and 
carbon tetrachloride are completely separate d from other components by a capillary gas 
chromatography column; conduct the test with an  electron capture detect or. Use the internal 
standard method to determine the amount.  
C.2 Materials and reagents 
 
C.2.1  Carrier gas: nitrogen, pur ity must be at least 99.995%; 
 C.2.2  Assisting gas (septum purge and make-up gas) : nitrogen with the same properties as the 
carrier gas;  C.2.3  Calibration compound: dichloromethane, 1,1-dichloroethane, 1, 2-dichloroethane, 
trichloromethane, 1,1,1-trichloroe thane, 1,1,2-trichloroethane and carbon tetrachlori de which are 
used for calibration, their purity must be at l east 99% (mass fraction) or a prescribed purity; 
 C.2.4  Dilution solvent: the organic solvent used to dilu te the sample, its purity must be at least 99% 
(mass fraction) or a prescribed purity. For example: ethyl acetate, n-hexane etc.  
C.2.5  Internal Standard: the compound wh ich is not contained in the sample that can be completely 
separated from other components of  the chromatogram. Its purity must be at least 99% (mass 
fraction) or a prescribed pur ity. For example: bromopropane. 
 
C.3 Instruments and devices 
 
C.3.1  Gas chromatograph, equipped with the following devices: 
 C.3.1.1  Sample injection port of the split injector, the liner of the vaporisation chamber is 
replaceable;  C.3.1.2 Programmed temperature controller 
 C.3.1.3  Electron Capture Detector (ECD); 
 C.3.1.4  Chromatography Column: must enable the test  components to be completely separated from 
other components, such as a (5 % phenyl) 95% methyl polysiloxane  capillary column or other 
equivalent types;  C.3.2  Sample Injection Device: 10µl microinjector; 
 C.3.3  Sample Preparation Bottle: a capacity of  10ml glass bottle, air-tight bottle lid; 
 - 16 - C.3.4  Scales: precision 0.1mg. 
 
C.4 Chromatographic analysis conditions 
 
Chromatography column: hp-5: (5% phenyl) 95% me thyl polysiloxane capillary column, 30m x 
0.25mm x 0.25µm or othe r equivalent types; 
 Temperature of the sample injection port: 250
oC; 
Column temperature: the initial temperature must be 40oC and maintained for 15 minutes, then the 
temperature is increased by increments of 10oC per minute until it reaches 150oC, maintaining this 
temperature for 2 minutes; then the temperature is increased by increments of 50oC per minute until 
it reaches 250oC, maintaining this temperature for 2 minutes; 
Temperature of the detector: 300oC; 
Flow rate of the carrier gas: 2.0ml/minute; Split ratio: sample split-injected, adjustable split ratio;  Note: In order to select the best test conditions of  the gas chromatograph, the test conditions of the 
gas chromatography can be selected on the basis of the characteristics of th e devices used and the 
actual conditions of the test sample. 
 
 
C.5 Test procedures 
 
C.5.1 Optimisation of chro matographic parameters 
 
According to the test conditions of the chroma tographic condition specifi ed in C.4, prescribed 
calibration compounds must be used to carry out op timised treatment, in order to maintain the 
optimum accuracy, stability and separation efficiency of the device. The sample size and the split ratio must correspond to each other, to avoid exceeding the capacity of the chromatographic 
column, and be within the linea r range of the device detector. 
 
C.5.2 Determination of the retention time of the test substances 
 
According to C.5.1 adjust the device to its best state, after the devi ce is steady, inj ect into 1.0µl 
standard solution which contains all the test subs tances. Record the retent ion time of each test 
substance. See Figure 1 for the peak sequence and retention time of each test substance. - 17 - Figure 1 The peak sequences of test s ubstances on HP-5 capillary column 
Peak 1 – dichloromethane;  Peak 2 – 1.1-dichloroethane;   
      Peak 3 – trichloromethane        Peak 4 – bromopropane;          Peak 5 – 1.1-trichloroethane;             Peak 6 – 1.2-dichloroethane;   
      Peak 7 – carbon tetrachloride;            Peak 8 – 1.1.2-trichloroethane; 
 
C.5.3  Test components in a qualitative sample: 
 
Weigh out about 2g of the sample, after diluting w ith a suitable amount of dilution solvent (C.2.4). 
Conduct tests in accordance with the test c onditions prescribed in C.5.1, and produce the 
determination of the test substances.  
C.5.4 Determination of the relative corr ection factor of the test components 
 
Weigh a certain amount (precise to 0.1mg) of the calib ration compound as approved in C.5.3 for 
each test component and place into the sample pr eparation bottle (C.3.3). The weighed mass must 
be the same mass as the content of each substan ce in the test sample, and then weigh out the 
internal standard (C.2.5) which has a similar mass as the test compounds and put it into the same 
sample preparation bottle. Use the dilution solven t (C.2.4) to dilute the mixture (the diluted 
concentration must be within the linear range of the device det ector. If the diluted concentration 
exceeds the stated range, then the diluting times must increase or use multiple dilution), seal the 
bottle and shake until the dilution is well mixed.  Under the same chromatographic conditions as the test sample, carry out parameter optimised 
treatment in accordance with C .5.1. Inject a suitable amount of the calibration compound into the 
gas chromatography and record the chromatogram.  The relative correction factor R
i of each test compound shall be de termined by the formula (C.1) 
respectively: 
- 18 -  
Where:  R
i – the relative correction factor of the compound i; 
mci – the mass of the compound i in  the calibration mixture, g; 
mis – the mass of the internal standard  in the calibration mixture, g; 
Ais – the peak area of the internal standard; 
Aci – the peak area of the compound i. 
Parallel test twice, take the mean va lue of the two test results as the R i value. Its relative deviation 
must be less than 5%, retain three significant numbers. 
 
C.5.5 Determination of the sample 
C.5.5.1  Weigh out exactly 2 grams of the sample (pr ecise to 0.1mg) and the internal standard 
which has the same mass as the test substanc es, put into the sample bottle (C.3.3). Use a 
suitable amount of dilution solvent (C.2.4) to dilu te the sample, seal the bottle and shake the 
mixture well. After the device is steady, inject  the 1.0µl sample and record the chromatogram. 
The content of each test substance in the sample is determined by the formula (C.2) 
respectively. 
  
Where: 
M
i – the mass fraction of the test component i in the sample, %; 
Ri – the relative correction factor of the test component i; 
mis – the mass of the internal standar d, unit of measurement is grams, g; 
ms – the mass of the sample, unit of measurement is grams, g; 
Ais – the peak area of the internal standard; 
Ai – the peak area of the test component i. 
Parallel test twice, take the mean value of  the two test results as the content of the 
test substance. Its relative devi ation must be less than 5%. 
C.5.5.2 The content of halohyrocarbon (M halohyrocarbon ) in the sample shall be determined by the 
formula (C.3):  
M
halohydrocarbon  = M dichloromethane  + M 1,1dichloroethane  + M 1,2 dichloroethane  +M 1,1,1 trichloroethane   
    +  M 1,1,2 trichloroethane + M carbon tetrachloride  +M chloroform 
 The test results must retain two significant digits.