GB 5175-2000 Food additive Sodium hydroxide

This standard specifies the requirements, test methods, inspection rules, marking, labeling, packaging, transportation, storage and safety of food additive sodium hydroxide. This standard applies to food additive sodium hydroxide produced by causticizing, simple diaphragm electrolysis and ion membrane methods, and is used as an acidity regulator in the food industry. GB 5175-2000 Food Additive Sodium Hydroxide GB5175-2000 Standard Download Decompression Password: www.bzxz.net

GB5175-2000
This standard is equivalent to the fourth edition of the US Food Chemicals Codex, namely FCCV (1996) "Sodium Hydroxide" to revise GB5175-1985 "Food Additive Sodium Hydroxide". The main technical differences with the US Food Chemicals Codex are as follows: In terms of determination methods, the determination of arsenic content in the US FCCN adopts the diethyldithiocarbamate silver colorimetric method, while this standard adopts the arsenic spot method. For lead content, the US FCCV adopts the dithiothreitol colorimetric method, while this standard adopts the dithiothreitol colorimetric method in parallel with the atomic absorption method, with the atomic absorption method being the arbitration method.
Compared with the original national standard, this standard cancels the two indicators of sodium chloride and ferric oxide; adds the indicators of lead, insoluble matter and organic impurities, and mercury content; the expression method of the indicator parameters of liquid sodium hydroxide is expressed by the method of converting to solid sodium hydroxide. This standard replaces GB5175-1985 from the date of implementation. Appendix A of this standard is a prompt appendix. This standard was proposed by the former Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Inorganic Chemical Branch of the National Technical Committee for Chemical Standardization and the Food Hygiene Supervision and Inspection Institute of the Ministry of Health. The drafting units of this standard are Tianjin Chemical Research and Design Institute, Guangzhou Haotian Chemical (Group) Co., Ltd., and Zhejiang Shangao Chemical Co., Ltd. The main drafters of this standard are Shi Jie, Su Peiji, Chen Xiangheng, Yu Jinyan, and Zhang Yuechan. This standard was first issued in 1985.
This standard is entrusted to the Inorganic Chemical Branch of the National Technical Committee for Chemical Standardization for interpretation. 364
1 Scope
National Standard of the People's Republic of China
Food additive-Sodium hydroxide
Food additive-Sodium hydroxide GB 5175—2000
Replaces GB5175---1985
This standard specifies the requirements, test methods, inspection rules, marking, labeling, packaging, transportation, storage and safety of food additive sodium hydroxide.
This standard applies to food additive sodium hydroxide produced by causticizing, simple diaphragm electrolysis and ion membrane methods, and is used as an acidity regulator in the food industry.
Molecular formula: NaOH
Relative molecular mass: 40.00 (according to the 1997 international relative atomic mass) 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB190—1990 Dangerous Goods Packaging Marking
Pictorial Marking for Packaging Storage and Transportation
GB 191—1990
GB/T 601—1988
GB/T 602--1988
GB/T 603-—1988
GB/T 6678—1986
GB/T 6682—1992
GB/T 8450-1987
GB/T 8451—1987
Chemical reagents Preparation of standard solutions for titration analysis (volume analysis) Preparation of standard solutions for impurity determination (negISO6353/1:1982) Chemical reagents
Chemical reagents
Preparation of preparations and products used in test methods (negISO6353/1:1982) General rules for sampling of chemical products
Specifications and test methods for water used in analytical laboratories (eqvISO3696:1987) Determination of arsenic in food additives
Test method for heavy metal limits in food additives GB/T11198.10—1989 Determination of mercury content in industrial sulfuric acid Cold atomic absorption spectrophotometry 3 Requirements
3.1 Appearance: Food additive solid sodium hydroxide is white or nearly white. Food additive liquid sodium hydroxide is a clear or slightly turbid, colorless or slightly colored liquid. 3.2 Food additive solid sodium hydroxide shall comply with the requirements of Table 1: Table 1
Total alkali content (as NaOH), %
Sodium carbonate (Na2CO:) content, %
(As) content, %
Approved by the State Administration of Quality and Technical Supervision on June 16, 2000
95.0~100.5
Implementation on December 1, 2000
Heavy metal (as Pb) content, %
Lead (Pb) content, %
Insoluble matter and organic impurities
Hg content, %
GB 5175--2000
Table 1 (End)
Note: When the actual measured result of the heavy metal content is less than 0.001%, the lead content may not be determined. 3.3 Food additives Liquid sodium hydroxide should meet the requirements of Table 2. Table 2
Total alkali content (in NaOH) (converted according to the labeled value of sodium hydroxide) Sodium carbonate (Na2CO) content (converted according to the labeled value of sodium hydroxide) Arsenic (As) content (on a dry basis)
Heavy metal (in Pb) content (on a dry basis) Lead (Pb) content (on a dry basis)
Mercury (Hg) content (on a dry basis)
Note: When the actual measured result of the heavy metal content is less than 0.001%, the lead content may not be determined. 4 Test method
By test
97.0~103.0
The reagents and water used in this standard, unless otherwise specified, refer to analytical pure reagents and grade 3 water specified in GB/T6682. The standard titration solution, impurity standard solution, preparation and products used in the test, unless otherwise specified, shall be prepared in accordance with the provisions of GB/T601, GB/T602 and GB/T603: Safety Tips: This product is a strong base, and like the strong acid used in the test, it is corrosive and should be handled with caution. If it splashes on the skin, rinse immediately with plenty of water.
4.1 Identification Test
4.1.1 The aqueous solution of this product can dissociate OH- and react with a strong alkaline reaction. 4.1.2 Identification of Sodium Ions
4.1.2.1 Instruments and Equipment
Glass rod with platinum wire burned on the top.
4.1.2.2 Operation Steps
Wet the clean platinum wire with hydrochloric acid and burn it on the flame until it is colorless; dip the sample and burn it in the colorless flame, and the flame will be bright yellow.
2 Determination of total alkali and sodium carbonate content
4.2.1 Method summary
Total alkali: The sample solution is titrated to the endpoint with methyl orange as the indicator solution and hydrochloric acid standard titration solution according to the instructions for the use of hydrochloric acid standard titration solution:
1 The US FCC N takes a sample once, first uses phenolic acid as the indicator solution, then uses methyl orange as the indicator solution, and uses sulfuric acid standard titration solution to titrate the test solution to determine the total alkalinity and sodium carbonate content. This standard takes a second sample, titrates with hydrochloric acid standard titration solution, and determines the total alkali with methyl orange as the indicator solution; then uses barium chloride to precipitate sodium carbonate, and uses phenolic acid as the indicator solution to determine the sodium hydroxide content. The sodium carbonate content is obtained by subtracting the sodium hydroxide content from the total alkali content. 366
Total alkali is determined by consumption.
GB5175—2000
Sodium carbonate content: Add barium chloride to the sample solution, and the sodium carbonate will be converted into barium carbonate precipitate; the sodium hydroxide in the solution is titrated to the end point with standard hydrochloric acid solution using phenol anhydride as the indicator solution, and the content of sodium hydroxide is measured. Subtract the sodium hydroxide content from the total alkali content to obtain the content of sodium carbonate.
4.2.2 Reagents and materials
4.2.2.1 Barium chloride solution: 100g/L.
Before use, use phenol anhydride as the indicator solution and adjust to pink with sodium hydroxide solution. 4.2.2.2 Standard hydrochloric acid titration solution: c(HCl) is about 1mol/L. 4.2.2.3 Phenol indicator solution: 10g/L.
4.2.2.4 Methyl orange indicator solution: 1g/L.
4.2.3 Analysis steps
4.2.3.1 Preparation of test solution
Use a weighing bottle of known mass to quickly weigh solid sodium hydroxide (38±1)g or liquid sodium hydroxide (50±1)g, accurate to 0.01g, put it into a 400ml. beaker, dissolve it with water, cool it to room temperature, transfer it to a 1000ml volumetric flask, add water to dilute to the scale, and shake it well. This is test solution A.
4.2.3.2 Determination
Use a pipette to transfer 50mL of test solution A, inject it into a 250mL stoppered conical flask, add 2 to 3 drops of methyl orange indicator solution, and titrate it in a closed manner with a magnetic stirrer until the solution turns orange. Use a pipette to transfer another 50mL of test solution A, inject it into a 250mL stoppered conical flask, and add 20ml.barium chloride solution, and then add 2 to 3 drops of phenolphthalein indicator solution. Under stirring with a magnetic stirrer, use hydrochloric acid standard titration solution to titrate in a closed manner until the solution turns pink. 4.2.4 Expression of analytical results
4.2.4.1 The total alkali content (in terms of NaOH) (X,) expressed as mass percentage is calculated according to formula (1): _ y/:c× 0. 040 00 × 100 =
X,(%) =
m×1000
80. 00 XV, : c
4.2.4.2 The sodium carbonate (Na2CO:) content in sodium hydroxide expressed as mass percentage (X,) is calculated according to formula (2): Xx(%) = Vi-V) ·cX0. 052 99 × 100 =105. 98 X (Vi - V) c
m×1000
-actual concentration of standard hydrochloric acid titration solution, mol/L; where: c—
V is the volume of standard hydrochloric acid titration solution consumed by titrating test solution A with phenolic acid as indicator, mL; V.—-the volume of standard hydrochloric acid titration solution consumed by titrating test solution A with methyl orange as indicator, mL; m
........( 2)
mass of solid sample, g;
the mass of sodium hydroxide expressed in grams equivalent to 1.00mL standard hydrochloric acid titration solution [c(HCI)=1.000mol/LI 0. 040 00-
0.05299--the mass of sodium carbonate expressed in grams equivalent to 1.00mL standard hydrochloric acid titration solution [c(HC1)=1.000mo1/L]. 4.2.4.3 The total alkali content (in terms of NaOH) (X.) of liquid sodium hydroxide expressed as a percentage relative to the labeled value is calculated according to formula (3): X
4.2.4.4 The sodium carbonate (Na2CO3) content (X.) in liquid sodium hydroxide expressed as a percentage relative to the labeled value is calculated according to formula (4): X,
Wherein: b—the labeled value of the concentration of liquid sodium hydroxide. 4.2.5 Allowable difference
GB5175—2000
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed: sodium hydroxide (NaOH): 0.10%;
sodium carbonate (Na2CO3): 0.05%.
4.3 Determination of arsenic content 1
Weigh (5.00±0.01)g of solid sodium hydroxide sample or liquid sample equivalent to (5.00±0.01)g of solid sodium hydroxide sample (converted to the percentage content of liquid sodium hydroxide measured), add about 20ml of water to dissolve or dilute, neutralize with hydrochloric acid solution (1+1) to neutrality (test with pH test paper), cool to room temperature, transfer to a 100mL volumetric flask, dilute to scale, shake well (dry filter if necessary, discard the initial filtrate), and set aside. This is test solution B. Www.bzxZ.net
Use a pipette to transfer 10mL of test solution B and place it in an arsenic determination bottle. The following is determined according to the arsenic spot method of GB/T8450. Use a pipette to transfer 1.5mL of arsenic standard solution (1mL solution contains 1μg arsenic) as the standard, and the following is determined according to the arsenic spot method of GB/T8450.
4.4 Determination of heavy metal content
Use a pipette to transfer 20 mL of test solution B into a 50 mL colorimetric tube, add 1 drop of phenolic acid indicator solution, adjust to pink with ammonia water (1+1), and perform the determination according to Chapter 6 of GB/T8451-1987. Use a pipette to transfer 2 mL of lead standard solution (1 mL of solution contains 10 μg of lead) as the standard, and perform the determination according to Chapter 6 of GB/T8451---1987.
4.5 Determination of lead content 2
4.5.1 Atomic absorption spectrophotometry (arbitration method) 4.5.1.1 Summary of the method
In dilute nitric acid medium, use an atomic absorption spectrophotometer at a wavelength of 283.3 nm and use an air-acetylene flame to determine by the standard addition method.
4.5.1.2 Reagents and materials
a) Nitric acid solution: 1+1;
b) Lead standard solution: 1mL solution contains 0.01mg lead, prepared before use. Preparation: Use a pipette to transfer 10mL of lead standard solution prepared according to GB/T602, place it in a 100mL volumetric flask, dilute with water to the scale, and shake well.
4.5.1.3 Instruments and equipment
a) Atomic absorption spectrophotometer (equipped with a lead hollow cathode lamp) Working conditions: Wavelength: 283.3nm; Flame: air-acetylene. 4.5.1.4 Analysis steps
Weigh about 10g of solid sodium hydroxide sample or liquid sodium hydroxide equivalent to about 10g of solid sodium hydroxide sample, accurate to 0.01g, dissolve in 50ml of water, adjust the pH value to neutral with nitric acid, and then transfer 1mL in excess to a 250mL volumetric flask, dilute to scale with water, and shake well.
Use a pipette to transfer 25mL of the test solution to four 100mL volumetric flasks, then use a pipette to add 0, 1.00, 2.00, and 3.00mL of the lead standard solution, dilute to scale with water, and shake well. Adjust the instrument to the optimal working conditions, adjust to zero with water, and measure the absorbance. Use the mass of lead as the horizontal axis and the corresponding absorbance as the vertical axis to draw a working curve. The point where the curve is extended in the opposite direction and intersects with the horizontal axis is the mass of lead in the test solution.
4.5.1.5 Expression of analysis results
The lead (Pb) content (X:) expressed as a mass percentage is calculated according to formula (5): Instructions:
1] The US FCC N adopts the silver diethyldithiocarbamate method, and this standard adopts the arsenic spot method. 2] The US FCCN adopts the dithiol colorimetric method, and this standard adopts the dithiol colorimetric method in parallel with the atomic absorption method, with the atomic absorption method being the arbitration method. 368
GB 5175-2000
Xs(%) = m × 10-3
X 100 =
Where: m,--the mass of lead in the test solution found from the working curve, mg; the mass of the sample, g.
4.5.1.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result, and the absolute difference of the parallel determination results shall not exceed 0.0004%. 4.5.2 Dithiocarbamide colorimetric method
Safety tips: This method uses highly toxic potassium cyanide during operation, which is prohibited from contact with skin or inhalation. The test solution after the test shall be treated according to Appendix A (Suggested Appendix) before discharge. 4.5.2.1 Method Summary
Under alkaline conditions, potassium cyanide solution is used to mask interfering metal ions other than lead. At pH = 10, dithiol-chloroform solution is used to extract lead in the sample and develop color with it. Compare with the standard colorimetric solution to determine whether the lead content is within the limit. 4.5.2.2 Reagents and Materials
a) Hydroxylamine hydrochloride;
b) Nitric acid solution: 1+9;
c) Ammonium citrate solution: 400g/L;
d) Potassium cyanide solution: 150g/L;
e) Ammonia-ammonium chloride buffer solution (A): pH = 10; f) Dithiol-chloroform solution: 0.02g/L; Preparation: Dissolve 0.02g of dithiol in 1L of trifluoromethane and store at 10°C away from light. g) Lead standard solution: 1mL of solution contains 0.010mg of lead. Preparation: Use a pipette to transfer 10.00 mL of the lead standard solution prepared according to GB/T602, place it in a 100 mL volumetric flask, dilute it to the mark with water, and shake it well. Prepare the dilution before use. 4.5.2.3 Analysis steps
Weigh about (0.50±0.01) g of solid sodium hydroxide sample or about (0.50±0.01) g of liquid sodium hydroxide equivalent to solid sodium hydroxide sample. Place it in a 50 mL colorimetric tube, add 25 mL of water to dissolve it, and adjust the pH to 8 with nitric acid solution. Add 5 mL of ammonium citrate solution, 5 mL of ammonia-ammonium chloride buffer solution, and 10 mL of potassium cyanide solution, and shake it well. Add 0.5 g of hydroxylamine hydrochloride and shake it well. Add 5 mL of dithiol-chloroform solution and shake it for 1 minute. After the solution is separated, the color of the dithiol-chloroform extraction layer shall not be redder than the standard colorimetric solution. The standard colorimetric solution is 0.50 ml of lead standard solution taken with a pipette and treated in the same way as the sample. 4.6 Determination of insoluble matter and organic impurities
Weigh (5.00 ± 0.01) g of solid sodium hydroxide and dissolve it in 100 mL of water. The solution is completely clear, colorless or slightly colored. 4.7 Determination of mercury content
4.7.1 Summary of the method
Same as Chapter 2 of GB/T11198.10-1989. 4.7.2 Reagents
4.7.2.1 Sulfuric acid solution: 1+1;
Others are the same as GB/T11198.10-1989, Chapter 3. 4.7.3 Instruments and equipment
Same as Chapter 4 of GB/T 11198.10-1989. 4.7.4 Drawing of working curve
Same as Chapter 6 of GB/T 11198.10-1989. 4.7.5 Analysis steps
4.7.5.1 Preparation of test solution
GB 5175-2000
Weigh (2.00±0.01)g of solid sodium hydroxide or liquid sodium hydroxide equivalent to (2.00±0.01)g of solid sodium oxide, place in a 100mL beaker, dissolve in 20mL of water, add 10mL of sulfuric acid solution (4.7.2.1), add 0.5mL of potassium permanganate solution, cover the beaker with a watch glass, boil for a few seconds, and then cool. 4.7.5.2 Preparation of blank test solution
Except that no sample is added, the same treatment as the test solution is carried out at the same time. 4.7.5.3 Determination
The test solution and blank test solution are measured according to 6.2 of GB/T11198.10--1989. 4.7.6 Expression of analysis results
The mercury (Hg) content (X.) expressed as mass percentage is calculated according to formula (6): X(%) (m=mo)×10×100 =
Where: m1—the mass of mercury in the test solution found from the working curve, mgm—the mass of mercury in the blank test solution found from the working curve, mg; m-the mass of the sample, g.
4.7.7 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results: solid sodium hydroxide is not more than 0.000005%. Liquid sodium hydroxide is not more than 0.00005%. 5 Inspection rules
5.1 This standard adopts type inspection and routine inspection. (6))
5.1.1 Type inspection
All seven indicators of solid sodium hydroxide and all six indicators of liquid sodium hydroxide specified in the requirements are type inspection items. Under normal circumstances, type inspection shall be carried out at least once every three months. 5.1.2 Routine inspection
Total alkali content, sodium carbonate, arsenic, heavy metals, lead, insoluble matter and organic impurities are routine inspection items and should be inspected in batches. 5.2 Each batch of products shall not exceed 300t.
5.3 The number of sampling units for solid sodium hydroxide, a food additive, shall be determined in accordance with the provisions of GB/T6678. When sampling, slowly insert the sampler to two-thirds of the depth of the container for sampling. Mix the collected samples, the total amount shall not be less than 500g, and divide them into two clean and dry plastic bags or plastic bottles with stoppers, and seal them.
When the food additive liquid sodium hydroxide is shipped by tank truck or storage tank, take out equal amounts of samples from the top, middle and bottom (the top is one-tenth of the liquid layer from the liquid surface, and the bottom is one-tenth of the liquid layer from the bottom of the liquid), mix them evenly, and the total sample volume shall not be less than 500mL. Put it in a plastic bottle and seal it. Paste a label on the plastic bottle, indicating: manufacturer name, product name, batch number or tank truck number, sampling date and name of the sampler. One bottle is used for inspection, and the other bottle is kept for three months for reference.
5.4 The food additive sodium hydroxide shall be inspected by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer shall ensure that all food additive sodium hydroxide shipped from the factory meets the requirements of this standard. 5.5 The user has the right to inspect and accept the food additive sodium hydroxide received in accordance with the provisions of this standard, and the inspection and acceptance shall be carried out within one month from the date of arrival of the goods.
5.6 If any index of the test result does not meet the requirements of this standard, samples should be taken from the double amount of packaging for retest. If even one index of the retest result does not meet the requirements of this standard, the whole batch of products shall be unqualified. 6 Marking and labeling
6.1 The packaging container of sodium hydroxide, a food additive, shall be firmly and clearly marked, including the manufacturer's name, address, product name, trademark, the words "food additive", net content, batch number or production date, production license number, this standard number, the "corrosive product" mark specified in GB190 and the "upward" mark and "wet-afraid" mark specified in GB191. 6.2 Each batch of products leaving the factory shall be accompanied by a quality certificate, including: the manufacturer's name, address, product name, trademark, the words "food additive", net content, batch number or production date, production license number, proof that the product quality meets this standard and this standard number. 7 Packaging, transportation and storage
7.1 Solid sodium hydroxide as a food additive shall be packaged in iron barrels or other airtight containers, and the packaging containers shall comply with relevant regulations. The barrel cover must be firmly sealed. The net content of each barrel is 200kg, and the flaky solid sodium hydroxide is 25kg. Liquid sodium hydroxide as a food additive shall be shipped in special tank trucks or storage tanks and cleaned regularly. Plastic barrels and tank trucks that meet the requirements of food packaging standards are allowed to be used to transport liquid sodium hydroxide or flaky sodium hydroxide as a food additive. 7.2 During transportation, sodium hydroxide as a food additive shall not be mixed with acids and toxic and hazardous substances and shall be prevented from collision. 7.3 Sodium hydroxide as a food additive shall be stored in a cool and dry place to avoid damage, contamination, moisture and contact with acids. 8 Safety
Sodium hydroxide is highly corrosive, and labor protection equipment such as protective glasses and rubber gloves must be worn during operation. 371
GB 5175—2000
Appendix A
Treatment of waste liquid containing potassium fluoride
(Indicative Appendix)
In order to prevent the pollution of waste liquid containing potassium cyanide, waste liquid containing potassium cyanide should be post-treated after daily analysis before discharge. A1 Method Summary
Under alkaline conditions, divalent iron and cyanide ions form stable complex ions. A2 Treatment Steps
Collect the waste liquid in a 500mlL beaker, add 50ml, 1200g/L ferrous sulfate solution, stir, and discharge after sufficient reaction. The above-mentioned reagents can all be industrial grade.Seal.
When the food additive liquid sodium hydroxide is shipped by tank truck or storage tank, take out equal amounts of samples from the top, middle and bottom (the top is one-tenth of the liquid layer from the liquid surface, and the bottom is one-tenth of the liquid layer from the bottom of the liquid), mix them, and the total sample volume shall not be less than 500mL. Put it in a plastic bottle and seal it. Paste a label on the plastic bottle, indicating: manufacturer name, product name, batch number or tank truck number, sampling date and name of the sampler. One bottle is used for inspection, and the other bottle is kept for three months for reference.
5.4 The food additive sodium hydroxide shall be inspected by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer shall ensure that all food additive sodium hydroxide shipped from the factory meets the requirements of this standard. 5.5 The user has the right to inspect and accept the food additive sodium hydroxide received in accordance with the provisions of this standard, and the inspection and acceptance shall be carried out within one month from the date of arrival of the goods.
5.6 If any index of the test result does not meet the requirements of this standard, samples should be taken from the double amount of packaging for retest. If even one index of the retest result does not meet the requirements of this standard, the whole batch of products shall be unqualified. 6 Marking and labeling
6.1 The packaging container of sodium hydroxide, a food additive, shall be firmly and clearly marked, including the manufacturer's name, address, product name, trademark, the words "food additive", net content, batch number or production date, production license number, this standard number, the "corrosive product" mark specified in GB190 and the "upward" mark and "wet-afraid" mark specified in GB191. 6.2 Each batch of products leaving the factory shall be accompanied by a quality certificate, including: the manufacturer's name, address, product name, trademark, the words "food additive", net content, batch number or production date, production license number, proof that the product quality meets this standard and this standard number. 7 Packaging, transportation and storage
7.1 Solid sodium hydroxide as a food additive shall be packaged in iron barrels or other airtight containers, and the packaging containers shall comply with relevant regulations. The barrel cover must be firmly sealed. The net content of each barrel is 200kg, and the flaky solid sodium hydroxide is 25kg. Liquid sodium hydroxide as a food additive shall be shipped in special tank trucks or storage tanks and cleaned regularly. Plastic barrels and tank trucks that meet the requirements of food packaging standards are allowed to be used to transport liquid sodium hydroxide or flaky sodium hydroxide as a food additive. 7.2 During transportation, sodium hydroxide as a food additive shall not be mixed with acids and toxic and hazardous substances and shall be prevented from collision. 7.3 Sodium hydroxide as a food additive shall be stored in a cool and dry place to avoid damage, contamination, moisture and contact with acids. 8 Safety
Sodium hydroxide is highly corrosive, and labor protection equipment such as protective glasses and rubber gloves must be worn during operation. 371
GB 5175—2000
Appendix A
Treatment of waste liquid containing potassium fluoride
(Indicative Appendix)
In order to prevent the pollution of waste liquid containing potassium cyanide, waste liquid containing potassium cyanide should be post-treated after daily analysis before discharge. A1 Method Summary
Under alkaline conditions, divalent iron and cyanide ions form stable complex ions. A2 Treatment Steps
Collect the waste liquid in a 500mlL beaker, add 50ml, 1200g/L ferrous sulfate solution, stir, and discharge after sufficient reaction. The above-mentioned reagents can all be industrial grade.Seal.
When the food additive liquid sodium hydroxide is shipped by tank truck or storage tank, take out equal amounts of samples from the top, middle and bottom (the top is one-tenth of the liquid layer from the liquid surface, and the bottom is one-tenth of the liquid layer from the bottom of the liquid), mix them, and the total sample volume shall not be less than 500mL. Put it in a plastic bottle and seal it. Paste a label on the plastic bottle, indicating: manufacturer name, product name, batch number or tank truck number, sampling date and name of the sampler. One bottle is used for inspection, and the other bottle is kept for three months for reference.
5.4 The food additive sodium hydroxide shall be inspected by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer shall ensure that all food additive sodium hydroxide shipped from the factory meets the requirements of this standard. 5.5 The user has the right to inspect and accept the food additive sodium hydroxide received in accordance with the provisions of this standard, and the inspection and acceptance shall be carried out within one month from the date of arrival of the goods.
5.6 If any index of the test result does not meet the requirements of this standard, samples should be taken from the double amount of packaging for retest. If even one index of the retest result does not meet the requirements of this standard, the whole batch of products shall be unqualified. 6 Marking and labeling
6.1 The packaging container of sodium hydroxide, a food additive, shall be firmly and clearly marked, including the manufacturer's name, address, product name, trademark, the words "food additive", net content, batch number or production date, production license number, this standard number, the "corrosive product" mark specified in GB190 and the "upward" mark and "wet-afraid" mark specified in GB191. 6.2 Each batch of products leaving the factory shall be accompanied by a quality certificate, including: the manufacturer's name, address, product name, trademark, the words "food additive", net content, batch number or production date, production license number, proof that the product quality meets this standard and this standard number. 7 Packaging, transportation and storage
7.1 Solid sodium hydroxide as a food additive shall be packaged in iron barrels or other airtight containers, and the packaging containers shall comply with relevant regulations. The barrel cover must be firmly sealed. The net content of each barrel is 200kg, and the flaky solid sodium hydroxide is 25kg. Liquid sodium hydroxide as a food additive shall be shipped in special tank trucks or storage tanks and cleaned regularly. Plastic barrels and tank trucks that meet the requirements of food packaging standards are allowed to be used to transport liquid sodium hydroxide or flaky sodium hydroxide as a food additive. 7.2 During transportation, sodium hydroxide as a food additive shall not be mixed with acids and toxic and hazardous substances and shall be prevented from collision. 7.3 Sodium hydroxide as a food additive shall be stored in a cool and dry place to avoid damage, contamination, moisture and contact with acids. 8 Safety
Sodium hydroxide is highly corrosive, and labor protection equipment such as protective glasses and rubber gloves must be worn during operation. 371
GB 5175—2000
Appendix A
Treatment of waste liquid containing potassium fluoride
(Indicative Appendix)
In order to prevent the pollution of waste liquid containing potassium cyanide, waste liquid containing potassium cyanide should be post-treated after daily analysis before discharge. A1 Method Summary
Under alkaline conditions, divalent iron and cyanide ions form stable complex ions. A2 Treatment Steps
Collect the waste liquid in a 500mlL beaker, add 50ml, 1200g/L ferrous sulfate solution, stir, and discharge after sufficient reaction. The above-mentioned reagents can all be industrial grade.
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