GB 16187-1996 Hygienic standard for hydrazoic acid and sodium azide in workplace air

This standard specifies the maximum permissible concentration of hydrazoic acid and sodium azide in the air of a workshop. This standard applies to all types of enterprises that produce and use sodium azide. GB 16187-1996 Hygienic Standard for Hydrazoic Acid and Sodium Azide in Workshop Air GB16187-1996 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Hydroxyacid and sodium azide in the air of workplace
Health standard for hydrazoic acid andsodium azide in the air of workplace Subject content and scope of application
This standard specifies the maximum allowable concentrations of hydrazoic acid and sodium azide in the air of workplace. This standard applies to all types of enterprises that produce and use sodium azide. 2 Hygiene requirements
The maximum allowable concentration of hydrazoic acid in the air of workplace is 0.2mg/m3. The maximum allowable concentration of sodium azide is 0.3mg/m3. 3 Monitoring and inspection methods
The monitoring and inspection methods of this standard adopt colorimetry, see Appendix A. 4 Supervision and implementation
Health and epidemic prevention agencies at all levels are responsible for supervising the implementation of this standard. GB16187-1996 approved by the State Administration of Technical Supervision on April 3, 1996
Implementation on September 1, 1996
A1 Principle
GB16187-1996
Appendix A
Spectrophotometric method
(Supplement)
Azide acid or azide in the air is absorbed in potassium hydroxide solution and reacts with trivalent iron to produce a brown-red complex, which is quantitatively determined by colorimetry. The detection limits of this method are: 4ug/10mL for hydrazoic acid; 6μg/10ml for sodium azide. A2 Apparatus
A2.1 Atmospheric sampler (or dust sampler). A2.2 Multi-hole glass plate absorption tube (or sampling clip). A2.3 Stoppered colorimetric tube, 10mL.
A2.4 Spectrophotometer.
A3 Reagents
A3.1 Absorption liquid: 0.001mol/L potassium hydroxide solution. A3.2N standard solution: Accurately weigh 0.1548g sodium azide, dissolve it in absorption liquid and dilute to 100mL, that is, 1.0ml=1.0mgN (stock solution). Dilute 10 times with absorption liquid when using, that is, 1.0mL=0.1mgN:. A3.35% ammonium sulfamate solution: Prepare with absorption liquid. A3.45% ferric chloride solution: 5g ferric chloride (FeCl:·6H2O) is dissolved in 25mL0.1mol/L hydrochloric acid, and water is added to 100mL. A4 Sampling
A porous glass plate absorption tube with 7ml absorption liquid is added, and the atmospheric sampler is used as the power to collect 10L of air at a speed of 0.5L/min (record temperature and pressure).
A5 Analysis steps
Take a 10ml colorimetric tube, add 0.5mL 5% ammonium sulfamate solution, and transfer the absorption liquid in the absorption tube to the colorimetric tube. Wash the absorption tube twice with the absorption liquid, and merge the washing liquid into the sample solution. Take another 7 colorimetric tubes, add appropriate amount of absorption liquid and 0.5ml 5% ammonium sulfamate solution to each tube, and then prepare standard tubes according to Table A1. Fill the sample tube and standard tube to the scale with absorption liquid, and finally add 0.5mL 5% ferric chloride solution to each tube, shake well, and colorimetrically quantify at a wavelength of 454nm. Table A1 Preparation of hydrazine acid standard tube
N；standard solution, mL
N: content, μg
A6 Calculation
Where: Concentration of hydrazine acid in air, mgm, 392
（Al）
GB 16187—1996bzxz.net
K-conversion coefficient. The coefficient converted to hydrazine acid according to the content of N；is 1.024, and the coefficient converted to sodium azide is 1.548;
-N content in the absorption tube sample, ug
Sampling volume under standard conditions, L.
A7 Precautions
A7.1 Nitrogen dioxide makes the solution fade, and the interference of nitrogen dioxide can be eliminated by adding ammonium aminosulfonate. The elimination limit is 1mg of nitrogen dioxide.
A7.2 Hydrazic acid and sodium azide cannot be determined separately. When sodium azide dust exists in the air, the sampling can be done by connecting two filter membranes in series in the sampling clip, and using a dust sampler to collect 50-100L of air at a rate of 10L/min. Then place the above filter membrane in a 10mL stoppered colorimetric tube, add 6-7ml 0.001mol/1. potassium hydroxide absorption liquid, and heat in a 60℃ water bath for 15-20min to elute. Take out the filter membrane, rinse with a small amount of absorption liquid, and add the liquid to the sample tube. The remaining steps are the same as for hydrazine. In the calculation, K is 1.548. Additional notes:
This standard was proposed by the Ministry of Health of the People's Republic of China. This standard was drafted by the Institute of Labor Hygiene and Occupational Diseases, Chinese Academy of Preventive Medicine. The main drafters of this standard are Lü Boqin and Zeng Zhaohui. This standard is interpreted by the Institute of Labor Hygiene and Occupational Diseases, Chinese Academy of Preventive Medicine, the technical management unit entrusted by the Ministry of Health. 393
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