GB 18536-2001 Occupational exposure limits for phosphorus oxychloride in workplace air

This standard specifies the maximum permissible concentration of phosphorus oxychloride in workshop air and its monitoring and testing methods. This standard is applicable to all types of industrial enterprises that produce and use phosphorus oxychloride. GB 18536-2001 Occupational exposure limits for phosphorus oxychloride in workshop air GB18536-2001 Standard download decompression password: www.bzxz.net

GB18536--2001
This standard is formulated based on on-site labor hygiene surveys, occupational epidemiological observations and animal experiments, and with reference to relevant foreign exposure limits; it is used as a health standard for workplace environmental monitoring and health supervision. This standard shall be implemented from May 1, 2002. Appendix A of this standard is the appendix to the standard. This standard is proposed by the Ministry of Health of the People's Republic of China. The drafting unit of this standard: Shandong Institute of Labor Hygiene and Occupational Disease Prevention and Control. The main drafters of this standard: Qiao Cibin, Zhang Shulai, Kang Aili, Liu Yi, Fu Ailing. This standard is entrusted to the Institute of Labor Hygiene and Occupational Diseases of the Chinese Academy of Preventive Medicine for interpretation. 644
1 Scope
National Standard of the People's Republic of China
Occupational exposure limit for pbosphorusoxychloride in the air of workplace This standard specifies the maximum allowable concentration of phosphorus oxychloride in the air of the workplace and its monitoring and inspection methods. This standard applies to various industrial enterprises that produce and use phosphorus oxychloride. 2 Hygiene requirements
The maximum permissible concentration of phosphorus oxychloride in workshop air is 0.3mg/m3. 3 Monitoring and inspection methods
The monitoring and inspection methods of this standard adopt the ammonium molybdate spectrophotometry method, see Appendix A. Approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on December 4, 2001-rKAoNrKAca-
GB18536-2001
Implementation on May 1, 2002
A1 Principle
GB 18536-2001
Appendix A
(Appendix to the standard)
Ammonium molybdate spectrophotometryWww.bzxZ.net
After phosphorus oxychloride in the air is absorbed by water, phosphoric acid and hydrochloric acid are generated. Phosphoric acid reacts with ammonium molybdate and chloramine to generate phosphomolybdenum blue, which is quantitatively measured by colorimetry.
A2 Apparatus
Porous glass plate absorption tube.
Air sampler: flow rate 0~1 l/min, A2.3
Colorimetric arm with stopper: 10 mL.
Spectrophotometer, 10mm colorimetric cup.
Constant temperature water bath.
A3 Reagents
A3.1 Absorption solution: distilled water is used for the experiment. A3.2 Sulfuric acid solution: c(1/2H,SO,)=8mol/L A3.3 Ammonium molybdate solution: 50g/L
A3.4 Stannous fluoride oil solution, dissolve 2.5g stannous chloride (SnClz·2I1.0)) in 100mL glycerol, store in a brown bottle at room temperature, can be used for one month.
A3.5 Standard solution: Weigh 0.4438g of dried potassium dihydrogen phosphate (KH,PO4), dissolve it in an appropriate amount of water, transfer it into a 500ml volumetric flask, add water to the scale, and hook it. 1ml of this solution contains 1mg of trifluorophosphorus oxychloride. Dilute it with water before use to make a 1ml standard solution containing 10μg of trichlorophosphorus.
A4 Sampling
Use a porous glass plate absorption tube filled with 5.0ml of absorption liquid to extract 10L of air at a flow rate of 0.5L/min. A5 Analysis steps
A5.1 Control experiment: With the same sample, bring the absorption tube filled with absorption liquid to the site. Except for not extracting air, the rest of the operations are the same as the sample, which serves as a blank control for the sample.
A5.2 Sample treatment: Wash the inner wall of the air inlet pipe 3 times with the absorption liquid in the absorption tube, pour the sample solution in the absorption tube into the stoppered colorimetric tube, wash the absorption tube 2 times with a small amount of water, add the washing liquid into the stoppered colorimetric tube, and dilute with water to 10 mL scale. A5.3 Drawing of standard curve: Take 6 stoppered colorimetric tubes and prepare the standard series according to Table A1. Table A1 Preparation of trifluorooxophosphine standard series
Standard solution/rnl
Absorbent solution/mJ
Content of trifluorophosphine/MK
GB18536—2001
Add 0.5mL sulfuric acid solution to each standard tube, stir well, add 0.2ml ammonium molybdate solution to each, shake, add 1 drop of linalool chloride solution to each, shake, place in a 50℃ constant temperature water bath, take out after 5min, use a 10mm colorimetric cup, at a wavelength of 700nm, with 0 tube as reference to measure the absorbance, plot the phosphorus oxychloride content (μg) against the absorbance, and draw a standard curve. A5.4 Sample determination: Take 5.0ml sample solution, operate in the same way as the standard tube, determine the absorbance, calculate the blank control value, and find out the content of trifluorophosphine (g) on ​​the standard curve.
A6 Calculation
A6.1 According to formula (A1), convert the volume of the collected air into the volume under standard conditions, Va + ViX
273 +^
Wherein: V.---·The volume of the air sample collected under standard conditions (air temperature 0C, atmospheric pressure 101.3kPa), L;
p---The temperature at the sampling point, kPa;
,.--The volume of the sample at t and p, I. A6:2 Calculate the concentration of trichloroethylene in the air by formula (A2). e = 2n1/V.
Where: t——concentration of trichloroammonium phosphate in air, mg/m3, m——amount of trichlorophosphine in sample, g:V, converted to sampling volume under standard conditions, I..A7 Explanation
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A7.1 The detection limit of this method is 0.77ug/5miL. The minimum detection concentration is 0.14mg/m3 (sampling 10L air). Standard curve range: 2~20/5mL, the equation is 3=0.0282+0.001. The correlation coefficient is 0.9996, and the coefficient of variation is 0.67±2.7%. A7.2 Sampling efficiency: Use a connected porous glass plate absorption tube and a large bubble absorption tube, respectively, and pump air at a flow rate of 0.5L/min for 10~20min. The sampling efficiency of the two absorption tubes is 100%. A7.3 Temperature has an effect on color development. The color development is fast and deep at high temperature, and slow and shallow at low temperature. 5 minutes at 50℃ is enough. A7.4 Since the reaction solution is acidic after the hydrolysis of phosphorus oxychloride, adding 0.5IL8mal/L (1/2H2SO4) sulfuric acid is the optimal acidity for this method. A7.5 If the air contains PCl, P,Os, H,P()4 and other phosphates, it may interfere with the detection of this method.
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