CIRCULAR

NATIONAL TECHNICAL REGULATION ON PERMISSIBLE EXPOSURE LIMIT VALUE OF 50 CHEMICALS AT THE WORKPLACE

Pursuant to the Law on occupational safety and health No. 84/2015/QH13 dated June 25, 2015;

Pursuant to the Law on technical regulations and standards No. 68/2006/QH13 dated June 29, 2006;

Pursuant to the Government's Decree No. 127/2007/ND-CP dated August 01, 2007 providing guidelines for implementation of the Law on technical regulations and standards;

Pursuant to the Government’s Decree No. 75/2017/ND-CP dated June 20, 2017 defining functions, tasks, powers and organizational structure of the Ministry of Health;

At the request of the Director of the Health Environment Management Agency;

The Minister of Health promulgates National technical regulation on permissible exposure limit value of 50 chemicals at the workplace.

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QCVN 03:2019/BYT - National technical regulation on permissible exposure limit value of 50 chemicals at the workplace is issued together with this Circular.

Article 2. Effect

1. This Circular comes into force from December 09, 2019.

2. Occupational safety and health standards with regard to Acetone, Acetic acid, Hydrogen chloride, Sulfuric acid, Ammonia, Aniline, Arsenic and compounds, Arsine, Benzene, n-Butanol, Cadmium and compounds, Carbon dioxide, Carbon disulfide, Carbon monoxide, Carbon tetrachloride, Chlorine, Chloroform, Chromium (III) compounds, Chromium (VI) compounds (water soluble), Chromium trioxide, Cobalt and compounds, Dichloromethane, Copper (dust), Copper (fume), Ethanol, Fluorine, Fluorides, Formaldehyde, n-Hexane, Hydrogen cyanide, Hydrogen sulfide, Zinc oxide, Manganese and compounds, Methanol, Methyl acetate, Aluminum and compounds, Nicotine, Nitrogen dioxide, Nitric oxide, Nitrobenzene, Nitrotoluene, Phenol, Selenium dioxide, Selenium and compounds, Sulfur dioxide, Toluene, 2, 4, 6 – Trinitrotoluene, Vinyl chloride, Petrol (Petrol distillates, gasoline) and Xylene issued together with the Decision No. 3733/2002/QD-BYT dated October 10, 2002 of the Minister of Health that is no longer valid from the effective date of this Circular.

Article 3. Responsibility for implementation

Chief of Ministry's Office, Chief Inspector of the Ministry, Director of Health Environment Management Agency, Directors/Directors General of Departments/General Departments affiliated to the Ministry of Health, heads of health agencies affiliated to other Ministries, and relevant organizations and individuals shall implement this Circular.

Difficulties that arise during the implementation of this Circular should be promptly reported to the Ministry of Health (via the Health Environment Management Agency) for consideration./.

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QCVN 03:2019/BYT

NATIONAL TECHNICAL REGULATION ON PERMISSIBLE EXPOSURE LIMIT VALUE OF 50 CHEMICALS AT THE WORKPLACE

Foreword

QCVN 03:2019/BYT is compiled by the Drafting Board for national technical regulations on occupational safety and health, presented by the Health Environment Management Agency for approval, appraised by the Ministry of Science and Technology and promulgated under the Circular No. 10/2019/TT-BYT dated June 10, 2019 by the Minister of Health.

NATIONAL TECHNICAL REGULATION ON PERMISSIBLE EXPOSURE LIMIT VALUE OF 50 CHEMICALS AT THE WORKPLACE

I. GENERAL PROVISIONS

1. Scope:

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2. Regulated entities:

This Regulation applies to occupational environment authorities, authorities and organizations performing occupational environment monitoring, and other organizations and individuals engaging in operations that generate chemicals in the workplace air.

3. Interpretation of terms

For the purposes of this Regulation, these terms are construed as follows:

(Names of chemicals are specified according to TCVN 5529:2010 - Chemical terms – Basic principle and TCVN 5530:2010 - Chemical terms – Nomenclature of chemical elements and compounds).

3.1. Acetone is a colorless and flammable liquid or fuming compound with mint-like odor. Chemical formula: (CH₃)₂CO. IUPAC name is Propanone. Other names: Acetona; dimethylformaldehyde; dimethylformehyde; dimethylketal; dimethyl ketone; ketone; ketone propane; β-ketopropane; methyl ketone; 2-propanone; propanone; pyroacetic acid; pyroacetic ether.

3.2. Acetic acid is a colorless liquid or crystalline solid with a sour, vinegar-like odor. Chemical formula: CH₃COOH. IUPAC name: acetic acid or ethanoic acid. Other names: 777 etch; glacial; acide acetique; acido acetic; aluminum etch 16-1-1-2; aluminum etch 82-3-15-0; micro-chrome etchant; copper, brass brite DIP 1127; dazzlens cleaner; essigsaeure; ethanoic acid; ethylic acid; freckle etch; glacial acetic acid (pure compound); glass etch; kodak 33 stop bath; kovar bright DIP (412X); KTI aluminum etch I/II; mae etchants; metal etch; methane carboxylic acid; poly etch 95%; vinegar (4 - 6% solution in water); vinegar acid; wet K-etch; wright etch.

3.3. Hydrogen chloride is a colorless to slightly yellow liquid or vapor with a sharp, pungent odor. Chemical formula: HCl. IUPAC name: Hydrogen chloride. Other names: Hydrogen chloride; muriatic acid; hydronium chloride; anhydrous hydrochloric acid.

3.4. Sulfuric acid is a colorless to dark brown liquid or vapor. Chemical formula:H₂SO₄. IUPAC name: sulfuric acid. Other names: Hydrogen sulfate; dihydrogen sulfate; oil of vitriol; dipping acid.

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3.6. Aniline is a is an organic, volatile compound in liquid form with the odor of rotten fish. Chemical formula: C₆H₅NH₂. IUPAC name: Phenylamine. Other names: Aniline; aminobenzene; benzenamine; aniline oil; anyvim; arylamine; benzeneamine; benzene, amino-; blue oil; huile d’aniline; phenylamine.

3.7. Arsenic and compounds: arsenic element and compounds in dust or vapor form. Chemical formula of arsenic: As. IUPAC name: arsenic. Inorganic arsenic compounds include arsenic trioxide (AS₂O₃); arsenic pentoxide (AS₂O₅) and some arsenic salts (excluding arsine). Other names of arsenic: Arsenic black; grey arsenic; ruby arsenic; metallic arsenic.

3.8. Arsine is a colorless and flammable vapor or gaseous compound with a slight garlic-like odor. Chemical formula: AsH₃. IUPAC name: Arsenic trihydride. Other names: Arsenic hydride; hydrogen arsenide; arsenous hydride; arseniuretted hydrogen; arsenic anhydride.

3.9. Benzene is a colorless, highly flammable and volatile liquid with a sweet odor. Chemical formula: C₆H₆. IUPAC name: Benzene. Other names: Benzol; benzole; phene; phenyl hydride; pyrobenzol.

3.10. N-butanol is a colorless liquid or fuming compound with alcoholic odor. Chemical formula: CH₃(CH₂)₃OH. IUPAC name is butan-1-ol. Other names: N-butyl alcohol; 1-butanol; propylcarbinol; alcowipe; alpha 100 flux; alpha 850-33 flux; aqua-sol flux; avantine; boron B-30; boron B-40; boron B-50; boron B-60; burmar lab clean.

3.11. Cadmium and compounds: cadmium element or its compounds in vapor, fume or dust form. Chemical formula: Cd, CdO. IUPAC name of Cd is Cadmium and that of CdO is Cadmium oxide. Other names of Cadmium: Cadmio; colloidal cadmium; elemental cadmium; kadmium.

3.12. Carbon dioxide is a colorless and odorless gas. Chemical formula: CO₂. IUPAC name is Carbon dioxide. Other names: Carbonic anhydride; acetylene black; elemental carbon.

3.13. Carbon disulfide is a liquid or fuming compound with ether-like odor. Chemical formula: CS₂. IUPAC name is Methanedithione. Other names: Carbon bisulfide; carbon sulfide; dithiocarbonic anhydride; schwefelkohlenstoff; sulphocarbonic anhydride; weeviltox.

3.14. Carbon monoxide is a colorless, odorless and tasteless gas that is slightly less dense than air. Chemical formula: CO. IUPAC name is Carbon monoxide. Other names: Carbonic oxide; carbon oxide; kohlenmonoxid.

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3.16. Chlorine is a colorless chemical element in vapor form. Chemical formula: Cl₂. IUPAC name is Chlorine. Other names: Bertholite; chlore; chlorine molecular; chlorro; dichlorine; poly I gas.

3.17. Chloroform is a colorless compound in vapor form. Chemical formula: CHCl₃. IUPAC name is Trichloromethane. Other names: Chloroforme; cloroformo; formyl trichloride; freon 20; methane trichloride; methane, trichloro-; methenyl trichloride; methyl trichloride; R 20 refrigerant; trichloroform; trichloromethane.

3.18. Chromium (III) compounds are compounds consisting of chromium in its +3 oxidation state. Chemical formula: Cr³⁺.

3.19. Chromi (VI) compounds (water soluble) are water-soluble compounds in vapor, fume or dust form of chromium salts and compounds of chromium in which it displays an oxidation state of +6. Chemical formula: Cr⁺⁶. Other names: Hexavalent chromium (Chromium VI).

3.20. Chromium trioxide is a colorless, dark red colored, crystalline, inorganic compound that is soluble in H₂SO₄, HNO₃, (C₂H₅)₂O, CH₃COOH, (CH₃)₂CO. Chemical formula: CrO₃. It is the acidic anhydride of chromic acid. IUPAC name is Chromium trioxide. Other name: Chromic anhydride; chromic acid (misnomer).

3.21. Cobalt and compounds: cobalt metal element or its compounds in vapor, fume or dust form. Cobalt metal is a silver-gray to black colored solid. Chemical formula of cobalt: Co. IUPAC name is Cobalt. Other names: Cobalt metal, cobalt (II), cobalt oxide.

3.22. Dichloromethane is a colorless compound in liquid or fuming form. Chemical formula: CH₂Cl₂. IUPAC name is Dichloromethane. Other names: Methylene chloride; methane dichloride; methylene bichloride; methylene dichloride; dichloromethane; solmethine; narkotil; solaesthin.

3.23. Copper and compounds (dust): copper metal or its compounds in dust form. Chemical formula of copper: Cu. IUPAC name is Copper. Other names of copper: 1721 gold; allbri natural copper; anac 110; arwood copper; bronze powder; C. I. pigment metal 2; cobre; copper bronze; elemental copper; gold bronze; kafar copper; M2 copper; Ml (copper); OFHC Cu; raney copper.

3.24. Copper and compounds (fume): copper metal or its compounds in fuming form. Chemical formula: Cu, CU₂O (copper oxide) and CuO (copper oxide fume).

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3.26. Fluorine is a yellow gaseous element with pungent odor. Chemical formula: F2. IUPAC name is Fluorine. Other names Fluorine-19; fluorues acide; saeure fluoride.

3.27. Fluorides include compounds in the air in vapor or dust form with odor and color depending on specific fluorine compounds. Fluorides are usually mixed with alkali metal in compounds such as NaF (sodium fluoride). Chemical formula: F^- or M_xF_yoride. IUPAC name is Fluoride. Other names: Fluoride ion; fluoride (1-); perfluoride.

3.28. Formaldehyde is a colorless gas with a pungent odor. The solution of approximately 37% by weight of formaldehyde gas in water is called formalin or formol. Chemical formula: HCHO. IUPAC name is formaldehyde or methanal. Other names: Formalin; methyl aldehyde; methylene oxide; methylene glycol; formol; aldehyde formique; fannoform; formic aldehyde; oxymehylene.

3.29. n-Hexane is a colorless, flammable and volatile liquid with a petroleum-like odor. Chemical formula: CH₃(CH₂)₄CH₃. IUPAC name is hexane. Other names: Sextane; exxsol hexane; genesolv 404 azeotrope; gettysolve-B; n-hexano; hexano; hexyl hydride; skellysolve B.

3.30. Hydrogen cyanide is a pale blue liquid or colorless gas with a faint bitter almond-like odor. Chemical formula: HCN. IUPAC name is formonitrile. Other names: Hydrogen cyanide; methanenitrile; hydrocyanic acid; prussic acid; zyklon B. The military designation of Hydrogen cyanide is AC.

3.31. Hydrogen sulfide is a colorless compound in liquid or fuming form with a strong odor of rotten eggs. Chemical formula: H₂S. IUPAC name is Hydrogen sulfide. Other names: Sulfur hydride; hydrothionic acid; dihydrogen monosulfide; dihydrogen sulfide; hydrogen sulfuric acid.

3.32. Zinc oxide is an amorphous, white or yellowish-white, odorless powder. Zinc oxide is found in the air in vapor, dust or fuming form. Chemical formula: ZnO. IUPAC name is Zinc oxide. Other names: Zinc white; Chinese white; zincite; emar; catamine; zinc peroxide; zincoid.

3.33. Manganese and compounds: metal element and compounds of manganese. They are found in the air in dust or fuming form. Chemical formula of manganese: Mn. IUPAC name is manganese. Other names of manganese: Colloidal manganese; cutaval; elemental manganese; manganese-55; manganese element; manganeso; tripart liquid; tronamag.

3.34. Methanol is a colorless, highly flammable and volatile liquid. Chemical formula: CH₃OH. IUPAC name is Methanol. Other names: Wood alcohol, methylol; wood spirit; carbinol; methyl alcohol.

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3.36. Aluminum and compounds: silvery-white metallic element and compounds of aluminum. They are found in the air in dust or fuming form. Chemical formula of aluminum: Al. IUPAC name is aluminum. Other names of aluminum: Alaun; alumina fibre; aluminio; aluminium; aluminium flake; aluminum 27; aluminum dehydrated; aluminum, aluminum powder; metana; metana aluminum paste; noral aluminum; noral extra fine lining grade; noral nonleafing grade.

3.37. Nicotine is a pale yellow to dark brown, oily liquid or powder with a slightly fishy odor. It is found in the air in vapor, fume or dust form. Chemical formula: C₁₀H₁₄N₂. IUPAC name is (S)-3-[1-methylpyrrolidin-2-yl] pyridine. Other names: Black leaf; campbell’s nico-soap; destruxol orchard spray; di-tetrahydronicotyrine; emo-Nib; flux MAAG; fumeto-bac; mach-Nic; 1-methyl-2-(3-pyridyl)pyrrolidine; 3-(N-methylpyrrolidino) pyridine; (s)-3-(1-Methyl-2-pyrrolidinyl)pyridine; 3-(1-methyl-2-pyrrolidinyl) pyridine; (-)-3-(1-Methyl-2-pyrrolidyl)pyridine; 1-3-(1-methyl-2-pyrrolidyl) pyridine; 3-(1-methyl- 2-pyrrolidyl)pyridine; niagra P. A. dust; nicocide; nicodust; nicofume; nicotina; 1-nicotine; nicotine alkaloid; nikotin; orthon-4 dust; orthon-5 dust; pyridine, 3-(1-methyl-2-pyrrolidinyl)-; pyridine, (s)-3-(1-methyl-2-pyrrolidinyl)- and salts; pyridine, 3-(tetrahydro-1-methylpyrrol-2-yl); β-pyridyl-α-N-methylpyrrolidine; tendust.

3.38. Nitrogen dioxide is a dark brown gas (above 21°C) or a yellow, fuming liquid (below 21°C) with a pungent odor. Chemical formula: NO₂; N₂O₄. IUPAC name is Nitrogen dioxide. Other names: Dinitrogen dioxide; dinitrogen dioxide, di-; dinitrogen tetroxide (N₂O₄); dioxido de nitrogeno; nitrogen peroxide; nitrogen tetroxide; nitrogen(IV) oxide, deutoxide of nitrogen.

3.39. Nitric oxide is a colorless gas. Chemical formula: NO. IUPAC name is nitrogen monoxide; oxidonitrogen. Other names: Nitric oxide; bioxyde d’azote; monoxido de nitrogeno; oxido nitrico; oxyde nitrique; stickmonoxyd; nitrogen(II) oxide.

3.40. Nitrobenzene is water-insoluble compound in liquid or fuming form with an almond-like odor. It has pale yellow color in liquid form. Chemical formula: C₆H₅NO₂. IUPAC name: Nitrobenzene. Other names: Nitrobenzol; nitrobenzole; oil of mirbane.

3.41. Nitrotoluene is a solid, liquid or fuming compound. Chemical formula: CH₃C₆H₄NO₂. It has o, m, p-isomers. IUPAC names of o-nitrotoluene, m-nitrotoluene and p-nitrotoluene are 1-methyl-2-nitrobenzene, 1-methyl-3-nitrobenzene and 1-methyl-4-nitrobenzene respectively. Other names: Methylnitrobenzene; nitrotoluene; mixed isomers; 4-nitrotoluene; 3-nitrotoluene; 2-nitrotoluene; ortho-nitrotoluene.

3.42. Phenol is a white crystalline solid that is volatile. Chemical formula: C₆H₅OH. IUPAC name is phenol. Other names: Acide carbolique; benzene hydroxy-; benzenol; carbolic acid; carbolsaure; fenol; hydroxybenzene; monohydroxybenzene; mono phenol; oxybenzene; phenic acid; phenole; phenyl alcohol; phenyl hydrate; phenyl hydroxide; phenylic acid; phenylic alcohol.

3.43. Selenium dioxide is a white to slightly reddish crystalline solid or yellow liquid or yellow-green vapor. Chemical formula: SeO₂. IUPAC name is Selenium dioxide. Other names: Selenium dioxide; selenium (IV) oxide; selenous anhydride; oxoselane oxide.

3.44. Selenium and compounds: selenium element and compounds with black allotropes or red solid phase. They are found in the air in dust form. Chemical formula of Selenium: Se. IUPAC name is selenium. Other names of selenium: Colloidal selenium; elemental selenium; selenate; selenio; selenium (colloidal); selenium alloy; selenium base; elenium dust; selenium element; selenium homopolymer; selenium powder.

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3.46. Toluene is a colorless liquid with a pungent odor. Chemical formula: C₆H₅CH₃. IUPAC name is toluene or methyl benzene. Other names: Antisal 1A; benzene, methyl-; methacide; methane, phenyl-; methylbenzol; phenylmethane; tolueno; toluol; tolu-sol; phenyl methane; anisen.

3.47. 2,4,6-Trinitrotoluene is a yellow solid or vapor, dust. Chemical formula: C₇H₅N₃O₆. IUPAC name is 2-methyl-1,3,5-trinitrobenzene. Other names: Entsufon; 1-methyl-2,4,6-trinitrotoluen; α-TNT; TNT-tolite; tolit; tolite; toluene, 2,4,6-trinitro,-(wet); sym-trinitrotoluene; 2,4,6-trinitrotoluene; trinitrotoluene; trinitrotoluene, wet; s-trinitrotoluol; sym-trinitrotoluol; 2,4,6-trinitrotoluol; trinitrotoluol; tritol; trotyl; trotyl oil; trinol; 2,4,6-trinitromethylbenzene; tritolo.

3.48. Vinyl chloride is a flammable organic chlorine compound in gaseous form. Chemical formula: C₂H₃Cl. IUPAC name is chloroethene. Other names: Chloroethylene; ethene chloro-; vinyl chloride monomer; vinyl chloride monomer; ethenechloro- (vinylchloride); monochloroethylene; monochloroethene.

3.49. Petrol is a liquid or gas compound. Petrol is a mixture of more than 200 hydrocarbons that have a general chemical formula of C_nH_2n+2 and have 4 – 12 carbon atoms. Other names: Gasoline; petrol.

3.50. Xylene is a colorless, volatile, water-insoluble liquid with aromatic odor. Xylene is a combination of 3 ortho-, meta- and para-isomers of dimethylbenzene. Chemical formula: C₆H₄(CH₃)₂. IUPAC names of o, m and p-isomers are 1,2-dimethyl benzene; 1,3-dimethyl benzene and 1,4-dimethyl benzene respectively. Other names: m-isomer: benzene, m-dimethyl-; benzene, 1,3-dimethyl-; m-dimethyl benzene; 1,3-dimethyl benzene; m-methyl toluene; m-xileno; m-xylene; 1,3-xylene; xylene, m-; m-xylol o-isomer: benzene-o-dimethyl; benzene-1,2-dimethyl-; o-dimethyl benzene; 1,2-dimethyl benzene; o-methyl toluene; 1,2-methyl toluene; o-xileno; o-xylene; 1,2-xylene; xylene, o-; o-xylol p-isomer: benzene-p-dimethyl; benzene-1,4-dimethyl; chromar; p-dimethyl benzene; 1,4-dimethyl benzene; p-methyl toluene; 4-methyl toluene; scintillar; p-xileno; p-xylene; 1,4-xylene; xylene, p-xylol.

3.51. Time Weighted Average (TWA) is the concentration of a chemical in the workplace air averaged over an 8-hour work shift or 40-hour workweek which the worker exposure should not exceed.

TWA is also applied in case of chemicals that do not have the short-term exposure limit (STEL) established. To be specific: worker exposure levels may exceed 3 times the TWA for no more than a total of 30 minutes during a work shift, and under no circumstances should they exceed 5 times the TWA although the 8-hour TWA is not exceeded.

3.52. Short Term Exposure Limit (STEL) is the concentration of a chemical in the workplace air averaged over a 15-minute period which the worker exposure should not exceed. Workers should not be exposed more than 4 times per work shift to concentrations between TWA and STEL. Each exposure shall not exceed 15 minutes. And there should be at least a 60-minute interval between exposures.

STEL shall be applied to chemicals that cause irritation to skin or mucous membranes, inhabitation or stimulation of central nervous system, acute or sub-acute injuries or irreversible tissue damage.

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3.54. Exposure duration is the time period workers are exposed to a chemical during a work shift.

3.55. Short-term sample is the sample that is measured or taken at a specific time during a short-term period which should be at least 15 minutes.

3.56. CAS (Chemical Abstracts Service) registry number is a unique numerical identifier assigned by the American Chemical Society to every chemical.

3.57. IUPAC: International Union of Pure and Applied Chemistry.

3.58. IARC: International Agency for Research on Cancer. IARC classifies chemicals into 5 categories based on the strength of evidence that they may cause cancer, including:

- Group 1: Chemicals (or mixtures) carcinogenic to humans.

- Group 2A: Chemicals (or mixtures) probably carcinogenic to humans.

- Group 2A: Chemicals (or mixtures) possibly carcinogenic to humans.

- Group 3: Chemicals (or mixtures) not classifiable as to its carcinogenicity to humans.

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II. TECHNICAL REQUIREMENTS

1. Permissible exposure limit values of chemicals at the workplace

Table 1. Maximum permissible exposure limit values of chemicals at the workplace

Unit: mg/m³

No.

Vietnamese name of chemical

English name

Chemical formula

Molecular mass

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TWA

STEL

Group of chemical as classified by IARC

1

Aceton

Acetone

(CH₃)₂CO

58,08

67-64-1

...

...

...

1000

-

2

Acid acetic

Acetic acid

CH₃COOH

60,08

64-19-7

25

...

...

...

-

3

Acid hydrochloric

Hydrogen chloride

HCl

36,46

7647-01-0

5,0

7,5

...

...

...

4

Acid sulfuric

Sulfuric acid

H₂SO₄

98,08

7664-93-9

1,0

2,0

1

...

...

...

Amonia

Ammonia

NH₃

17,03

7664-41-7

17

25

-

6

...

...

...

Aniline

C₆H₅NH₂

93,13

62-53-3

4,0

-

3

7

Arsenic và hợp chất

...

...

...

As

74,92

7440-38-2

0,01

-

1

8

Arsin

Arsine

...

...

...

77,95

7784-42-1

0,05

-

1

9

Benzen

Benzene

C₆H₆

...

...

...

78,12

5,0

15,0

1

10

n-Butanol

n-Butanol

C₄H₉OH

74,12

...

...

...

150

-

-

11

Cadmi và hợp chất

Cadmium and compounds

Cd

CdO

112,41

...

...

...

7440-43-9

1306-19-0

0,005

-

1

12

Carbon dioxide

Carbon dioxide

CO₂

...

...

...

124-38-9

9.000

18.000

-

13

Carbon disulfide

Carbon disulfide

CS₂

76,13

...

...

...

15

25

-

14

Carbon monoxide

Carbon monoxide

CO

28,01

630-08-0

...

...

...

40

-

15

Carbon tetrachloride

Carbon tetrachloride

CCl₄

153,84

56-23-5

10

...

...

...

2B

16

Chlor

Chlorine

Cl₂

70,90

7782-50-5

1,5

3,0

...

...

...

17

Chloroform

Chloroform

CHCl₃

119,37

67-66-3

10

20

2B

...

...

...

Chromi (III) (dạng hợp chất)

Chromium (III) compounds

Cr³⁺

52

16065-83-1

0,5

-

3

19

...

...

...

Chromium (VI) compounds (water soluble)

Cr⁶⁺

-

1333-82-0

0,01

-

1

20

Chromi (VI) oxide

...

...

...

CrO₃

99,99

1333-82-0

0,05

-

1

21

Cobalt và hợp chất

Cobalt and compounds

...

...

...

58,93

7440-48-4

0,05

-

2B

22

Dichloromethan

Dichloromethane

CH₂Cl₂

...

...

...

75-09-2

50

-

2A

23

Dồng và hợp chất (dạng bụi)

Copper and compounds (dust)

Cu

63,55

...

...

...

0,5

-

-

24

Dồng và hợp chất (dạng hơi, khói)

Copper and compounds (fume)

Cu

CuO

CuO₂

...

...

...

79,55

95,55

7440-50-8

1317-38-0

1317-39-1

0,1

-

-

25

...

...

...

Ethanol

CH₃CH₂OH

46,08

64-17-5

1.000

3.000

1

26

Fluor

...

...

...

F₂

38,00

7782-41-4

0,2

0,4

-

27

Fluoride

Fluorides

...

...

...

19,00

16984-48-8

1,0

-

3

28

Formaldehyde

Formaldehyde

HCHO

...

...

...

50-00-0

0,5

1,0

1

29

n-Hexan

n-Hexane

CH₃(CH₂)₄CH₃

86,20

...

...

...

90

-

-

30

Hydro cyanide

Hydrogen cyanide

HCN

27,03

74-90-8

...

...

...

0,6

-

31

Hydro sulfide

Hydrogen sulfide

H₂S

34,08

7783-06-4

10

...

...

...

-

32

Kẽm oxide (dạng khói, bụi)

Zinc oxide (dust, fume)

ZnO

81,37

1314-13-2

5,0

-

...

...

...

33

Mangan và các hợp chất

Manganese and compounds

Mn

54,94

7439-96-5

0,3

-

-

...

...

...

Methanol

Methanol

CH₃OH

32,04

67-56-1

50

100

-

35

...

...

...

Methyl acetate

CH₃COOCH₃

74,09

79-20-9

100

250

-

36

Nhôm và các hợp chất

...

...

...

Al

26,98

7429-90-5

2,0

-

-

37

Nicotin

Nicotine

...

...

...

162,23

54-11-5

0,5

-

-

38

Nitơ dioxide

Nitrogen dioxide

NO₂

...

...

...

10102-44-0

5,0

10

-

39

Nitơ monoxide

Nitric oxide

NO

30,01

...

...

...

10

-

-

40

Nitro benzen

Nitrobenzene

C₆H₅NO₂

123,12

98-95-3

...

...

...

-

2B

41

Nitro toluen

Nitrotoluene

CH₃C₆H₄NO₂

137,15

99-99-0

99-08-1

...

...

...

11

-

3

3

2A

42

Phenol

Phenol

C₆H₅OH

...

...

...

108-96-2

4,0

-

3

43

Selen dioxide

Selenium dioxide

SeO₂

110,96

...

...

...

0,1

-

3

44

Selen và các hợp chất

Selenium and compounds

Se

78,96

7782-49-2

...

...

...

-

3

45

Sulfur dioxide

Sulfur dioxide

SO₂

66,06

7446-09-5

5,0

...

...

...

3

46

Toluen

Toluene

C₆H₅CH₃

92,15

108-88-3

100

300

...

...

...

47

2,4,6 -

Trinitrotoluen

(TNT)

2,4,6 -

Trinitrotoluene

C₇H₅N₃O₆

227,15

118-96-7

...

...

...

-

3

48

Vinyl chloride

Vinyl chloride

C₂H₃Cl

62,50

75-01-4

1,0

...

...

...

1

49

Xăng

Petrol (Petrol distillates, gasoline)

C_nH_2n+2

99,99

8006-61-9;

89290-81-5

300

...

...

...

2A

50

Xylen

Xylene

C₆H₄(CH₃)₂

106

1330-20-7

100

300

...

...

...

2. Formula for conversion from ppm (part per million) to mg/m3 of an analyte (vapor or gas) in the air

C (mg/m³)

=

ppm x Wm

24,45

Where:

- C (mg/m³): The concentration of the analyte in the air expressed in mg/m³.

- ppm: The concentration of the analyte in the air in ppm.

- Wm: The molecular weight of the analyte.

...

...

...

3. Adjusted TWA for exposure duration longer than 8 hours per workday

The following formula shall be adopted:

TWAn

=

8

x

(24 - h)

x

TWA

...

...

...

16

Where:

- TWAn: The adjusted TWA for exposure duration longer than 8 hours per workday (mg/m³).

- TWA: The TWA for exposure duration of 8 hours/workday (mg/m³) of the corresponding chemical prescribed in the above Table 1.

- h: The actual exposure hours in a workday (h > 8).

4. Adjusted TWA for exposure duration longer than 40 hours per workweek

The following formula shall be adopted:

TWA_t =

40

...

...

...

(168 - H)

x TWA

H

128

Where:

- TWAt: The adjusted TWA for exposure duration longer than 40 hours per workweek (mg/m³).

- TWA: The TWA for exposure duration of 8 hours/workday and 40 hours/workweek (mg/m3) of the corresponding chemical prescribed in the above Table 1.

- H: The actual exposure hours in a workweek (H>40).

5. Calculation of actual TWA exposure values

...

...

...

TWA is calculated by adopting the following formula:

TWA = (C1.T1 + C2.T2 +...+ Cn.Tn) : T

Where:

- TWA: Time-weighted average exposure (mg/m³).

- C1; C2;...;Cn: The actual concentrations (mg/m³) measured during the corresponding measuring durations of T1;T2;...; Tn (minutes).

+ Samples may be measured or taken once with the measuring duration equal to exposure duration in a work shift in case of low-concentration chemicals.

+ There should be several sampling times (2,3,4,..., n times) with different measuring durations depending on the concentration of chemicals at the sampling point for the purpose of preventing overloading of filter paper or sampler, provided that total measuring duration shall equal total exposure duration.

- T: Total exposure duration (expressed in minutes).

+ If total exposure duration is less than or equal to 8 hours/workday, total exposure duration may be 8 hours and T equals 480 (minutes).

...

...

...

Samples may be taken with total measuring duration equal to at least 80% of exposure duration. In such case, T will be total measuring duration (expressed in minutes). In such case, exposure values for remaining time period will be considered to be same as those for the measured time period.

E.g.: A worker or a group of workers is exposed to formaldehyde over 6 hours per workday; the measured average concentration during 6 hours is 0,8 mg/m³; that worker or group of workers takes rest or performs other duties without exposing to formaldehyde in the remaining 2-hour period. In this case, TWA is calculated as follows:

TWA = (0,8mg/m³ x 6 hours + 0mg/m³ x 2 hours): 8 hours = 0,6mg/m³

5.2. Calculation of TWA when total measuring duration is less than total exposure duration

When evaluating the TWA value, samples should be measured or taken during the work shift with total measuring duration equal to total exposure duration. Because of restrictions on personnel, equipment and working conditions, short-term samples may be taken to serve the evaluation of TWA value as follows:

Based on the production process, each period during which the generation or dispersion of chemicals is fairly stable shall be determined and then representative samples shall be randomly taken for such each period. The quantity and length of time periods depend on the fluctuation of chemicals generated or dispersed during the work shift. In case chemicals are said to be generated or dispersed stably during the work shift, the quantity of time periods may be 2 (n = 2) and these periods shall have the same length which must be equal a half of total exposure duration.

TWA is calculated by adopting the following formula:

TWA = (C1.K1 + C2.K2 +...+ Cn.Kn) : T

Where:

...

...

...

- C1; C2;...; Cn: The average concentration (mg/m³) measured during time periods of K1; K2;...; Kn (minutes).

- K1; K2;...; Kn: Time periods in a work shift (minutes). Sum of time periods K1 + K2 + ... + Kn shall equal total hours of a work shift.

- T: Total exposure duration (expressed in minutes).

+ If total exposure duration is less than or equal to 8 hours/workday, total exposure duration may be 8 hours and T equals 480 (minutes).

+ If total exposure duration is longer than 8 hours/workday, T will be the actual exposure time period.

The average concentration (C1; C2;...; Cn) in time periods of a work shift shall be calculated by adopting the following formula:

Cx = (N1 + N2 +...+ Nn): n

Where:

- Cx: The average concentration for the time period Kx (mg/m³) and X = 1; 2;...;n.

...

...

...

- n: Total samples randomly taken during the time period Kx. (n>2)

Short-term samples must be taken within similar measuring durations.

E.g.: The dispersion of ammonia is assessed to be stable during the 8-hour work shift upon the preliminary observation at a workshop, total measured period shall be divided into 2 period (each time period shall be 4 hours). The concentrations randomly measured at any 2 times during the first 4-hour period are 14 mg/m³ and 13 mg/m³ and those randomly measured at any 2 times during the last 4-hour period are 17 mg/m³ and 18 mg/m³.

In such case, TWA is calculated as follows:

TWA = [(14 + 13)mg/m³ : 2] x 4 hours + [(17 + 18)mg/m³ : 2] x 4 hours]: 8 hours

= 15,5mg/m³

III. DETERMINATION METHODS

1. Method for determination of acetone [(CH₃)₂CO] is provided for in the Appendix No. 1 enclosed herewith.

2. Method for determination of acetic acid (CH₃COOH) is provided for in the Appendix No. 2 enclosed herewith.

...

...

...

4. Method for determination of sulfuric acid (H₂SO₄) is provided for in the Appendix No. 4 enclosed herewith.

5. Method for determination of ammonia (NH₃) is provided for in the Appendix No. 5 enclosed herewith.

6. Method for determination of aniline (C₆H₅NH₂) is provided for in the Appendix No. 6 enclosed herewith.

7. Method for determination of arsenic (As) and compounds is provided for in the Appendix No. 7 enclosed herewith.

8. Method for determination of arsine (ASH₃) is provided for in the Appendix No. 8 enclosed herewith.

9. Method for determination of benzene (C₆H₆) is provided for in the Appendix No. 9 enclosed herewith.

10. Method for determination of n-Butanol [(CH₃(CH₂)₃OH] is provided for in the Appendix No. 10 enclosed herewith.

11. Method for determination of cadmium (Cd) and compounds is provided for in the Appendix No. 11 enclosed herewith.

12. Method for determination of carbon dioxide (CO₂) is provided for in the Appendix No. 12 enclosed herewith.

...

...

...

14. Method for determination of carbon monoxide (CO) is provided for in the Appendix No. 14 enclosed herewith.

15. Method for determination of carbon tetrachloride (CCl₄) is provided for in the Appendix No. 15 enclosed herewith.

16. Method for determination of Chlorine (Cl₂) is provided for in the Appendix No. 16 enclosed herewith.

17. Method for determination of chloroform (CHCl₃) is provided for in the Appendix No. 17 enclosed herewith.

18. Method for determination of chromium (III) compounds (Cr³⁺) is provided for in the Appendix No. 18 enclosed herewith.

19. Method for determination of chromium (VI) compounds (water soluble, Cr⁺⁶) is provided for in the Appendix No. 19 enclosed herewith.

20. Method for determination of chromium trioxide (CrO₃) is provided for in the Appendix No. 20 enclosed herewith.

21. Method for determination of cobalt (Co) and compounds is provided for in the Appendix No. 21 enclosed herewith.

22. Method for determination of cichloromethane (CH₂Cl₂) is provided for in the Appendix No. 22 enclosed herewith.

...

...

...

24. Method for determination of copper (Cu) and compounds (fume) is provided for in the Appendix No. 24 enclosed herewith.

25. Method for determination of ethanol (CH₃CH₂OH) is provided for in the Appendix No. 25 enclosed herewith.

26. Method for determination of Fluorine (F₂) is provided for in the Appendix No. 50 enclosed herewith.

27. Method for determination of fluorides (F^-) is provided for in the Appendix No. 26 enclosed herewith.

28. Method for determination of formaldehyde (HCHO) is provided for in the Appendix No. 27 enclosed herewith.

29. Method for determination of n-Hexane [CH₃(CH₂)₄CH₃] is provided for in the Appendix No. 28 enclosed herewith.

30. Method for determination of hydrogen cyanide (HCN) is provided for in the Appendix No. 29 enclosed herewith.

31. Method for determination of hydrogen sulfide (H₂S) is provided for in the Appendix No. 30 enclosed herewith.

32. Method for determination of zinc oxide (ZnO) (dust, fume) is provided for in the Appendix No. 31 enclosed herewith.

...

...

...

34. Method for determination of methanol (CH₃OH) is provided for in the Appendix No. 33 enclosed herewith.

35. Method for determination of methyl acetate (CH₃COOCH₃) is provided for in the Appendix No. 34 enclosed herewith.

36. Method for determination of aluminum (Al) and compounds is provided for in the Appendix No. 35 enclosed herewith.

37. Method for determination of nicotine is provided for in the Appendix No. 36 enclosed herewith.

38. Method for determination of nitrogen dioxide (NO₂) is provided for in the Appendix No. 37 enclosed herewith.

39. Method for determination of nitric oxide (NO) is provided for in the Appendix No. 38 enclosed herewith.

40. Method for determination of nitrobenzene (C₆H₅NO₂) is provided for in the Appendix No. 39 enclosed herewith.

41. Method for determination of nitrotoluene (CH₃C₆H₄NO₂) is provided for in the Appendix No. 40 enclosed herewith.

42. Method for determination of phenol (C₆H₅OH) is provided for in the Appendix No. 41 enclosed herewith.

...

...

...

44. Method for determination of selenium (Se) and compounds is provided for in the Appendix No. 43 enclosed herewith.

45. Method for determination of sulfur dioxide (SO₂) is provided for in the Appendix No. 44 enclosed herewith.

46. Method for determination of toluene (C₆H₅CH₃) is provided for in the Appendix No. 45 enclosed herewith.

47. Method for determination of 2,4,6-trinitrotoluene (TNT) is provided for in the Appendix No. 46 enclosed herewith.

48. Method for determination of vinyl chloride (C₂H₃Cl) is provided for in the Appendix No. 47 enclosed herewith.

49. Method for determination of petrol (petrol distillates, gasoline) (C_nH_2n+2) is provided for in the Appendix No. 48 enclosed herewith.

50. Method for determination of xylene [(CH₃)₂C₆H₄] is provided for in the Appendix No. 49 enclosed herewith.

51. Methods for determination of concentrations of chemicals in the air by using electronic measuring devices are provided for in the Appendix No. 50 enclosed herewith.

52. Determination methods which are mentioned in other national or international standards and have their accuracy proved equal to or higher than those mentioned in this Regulation shall be accepted. Under specific circumstances with specific requirements, determination methods that are standards or other methods meeting the set requirements may be employed.

...

...

...

1. Enterprises that have their workers exposed to chemicals must carry out monitoring of chemicals at the workplace on a periodical basis of at least every year in accordance with the Labour Code and the Law on occupational safety and health.

2. Employers are required to provide their workers with adequate protective equipment which should be conformable with working environment and regulations of the Law on occupational safety and health.

3. In case the concentrations of chemicals at the workplace exceed the permissible exposure limit values, employers must immediately adopt measures for improving working environment and protecting workers’ health in accordance with regulations of the Law on occupational safety and health.

V. IMPLEMENTATION ORGANIZATION

1. The Health Environment Management Agency affiliated to the Ministry of Health shall lead and coordinate with relevant authorities to guide and organize the implementation of this Regulation.

2. If any national or international standard or any legislative document referred to in this Regulation is amended or superseded, the new one shall apply.