Maximum allowable dust concentration

In accordance with GB 16297-1996, the Comprehensive Emission Standards for Air Pollutants, the maximum allowable emission concentrations are as follows: for carbon black dust and dye dust, it is 18 mg/m3; for glass wool dust, quartz dust, and slag wool dust, it is 60 mg/m3; for other pollutants, it is 120 mg/m3. Additionally, the maximum allowable emission rates must also be complied with, in the case of emissions through exhaust stacks. This post was last edited by johncom on 2009-4-5 16:42]

The maximum allowable concentration actually comes from the \"Health Standards for the Design of Industrial Enterprises,\" and it applies to the air that people are exposed to, which can be divided into residential areas and workshops. In fact, it represents the highest level of assurance that, under certain conditions, health will not suffer any significant damage. Its target is the area around the pollution source. Additionally, **environmental air quality standards also set standard limits, which apply to the overall environment of a given area; they represent, of course, the minimum requirements necessary to protect human health in the long term.

The maximum allowable concentration specified in the \"Hygienic Standards for Industrial Enterprise Design\" is the value that the dust concentration in the air at workers’ work locations must not exceed; a work location refers to the place where workers spend time frequently or regularly during the production process. 【Validity】Valid 【Name of Regulation】Hygienic Standards for the Design of Industrial Enterprises (TJ36—79) 【Issuing Authorities】Ministry of Health and others 【Date of Issuance】September 30, 1979 【Date of Implementation】September 30, 1979 【Full Text】Hygienic Standards for the Design of Industrial Enterprises (TJ36—79) Chapter 1 General Provisions Article 1 These standards are formulated in order to implement the health policy of \"prevention first,\" as well as the provisions in the Constitution regarding the protection of the environment and natural resources, the prevention and control of pollution and other environmental hazards, and the improvement of working conditions and labor protection. They aim to ensure that the design of industrial enterprises meets hygienic requirements, protect people’s health, and promote the development of industrial and agricultural production. Article 2: When designing industrial enterprises, it is necessary to adhere to the principles of self-reliance and a combination of domestic and foreign technologies. Advanced and effective technologies should be actively adopted to eliminate dust, toxins, and other harmful substances, as well as \"wastewater, waste gas, and waste residues\", during the production process, so as to minimize or completely avoid their generation ； For those aspects that cannot be completely eliminated during the production process, necessary comprehensive preventive and control measures should also be taken to ensure that industrial enterprises are designed in accordance with the relevant provisions of this standard. The design of industrial enterprises shall also comply with the relevant provisions of current standards regarding the discharge of industrial \"three wastes\". Article 3: For newly built, renovated, expanded, or continued industrial enterprises, facilities for controlling various harmful factors must be designed, constructed, and put into operation simultaneously with the main project. The relevant competent departments must, in conjunction with the construction commissions, health, labor, and environmental protection authorities of the provinces, cities, and autonomous regions where the industrial enterprises are located, select site locations carefully, thoroughly review the designs, carry out proper completion inspections, and enforce strict quality controls. Health authorities at all levels must mobilize the public, work closely with relevant departments, and strictly supervise the implementation of these standards. Article 4: This standard applies to large and medium-sized industrial enterprises undergoing new construction, renovation, expansion, or continuation of operations. Small industrial enterprises that cause significant toxicity shall also comply with the relevant provisions of this standard. Existing industrial enterprises that pose pollution risks should also take effective measures to gradually meet the relevant requirements of these standards. Note: The criteria for classifying industrial construction projects as large, medium, or small shall be in accordance with **current regulations. Chapter 2: Hygienic Protection of the Atmosphere, Water Sources, and Soil Section 1: Site Selection and Atmospheric Hygienic Protection Article 5: The areas designated for industrial enterprises’ production zones, residential areas, waste storage sites, and wastewater treatment facilities, as well as the sources of drinking water, as well as the locations where industrial wastewater and domestic sewage are discharged, should all be selected simultaneously, and such selections must comply with the requirements of local development plans. Article 6: When selecting a site for a factory, it is necessary to prevent pollution of the atmosphere, water sources, and soil caused by the dispersion of industrial exhaust gases, the discharge of industrial wastewater, and the accumulation of industrial waste residues. Article 7 Industrial enterprises that generate harmful substances such as toxic gases, smoke, fog, dust, as well as noise and vibration that cause significant harm shall not be constructed in residential areas. Article 8: Industrial enterprises that emit harmful substances into the atmosphere should be located upwind of the wind direction with the lowest frequency in summer in residential areas. Industrial enterprises that discharge harmful industrial wastewater should be located downstream of local sources of drinking water. Article 9: When arranging industrial enterprises or workshops of different types within an industrial zone or factory complex, it is necessary to avoid mutual interference. Article 10: The orientation of a building shall ensure good natural lighting and ventilation inside, while also preventing excessive exposure to sunlight. The distance between buildings should generally not be less than the height of the taller of the two buildings (from the ground to the roof edge). Article 11: Industrial enterprises that generate hazardous substances shall not construct any other residential buildings within their production areas, except for duty rooms. Maximum Allowable Concentrations of Hazardous Substances in Residential Area Air Table 1 |--------------------------------------------------------------------------------------------------| | Code| Maximum Allowable Concentration| Code| Maximum Allowable Concentration| | Substance Name| (mg/m³)| | Substance Name| (mg/m³)| |----------------------| | |----------------------| | No.| One-time| Daily Average| | No.| One-time| Daily Average| |---|-----------------|---------|-----------| |--|-------------------|---------|-----------| | 1 | Carbon monoxide | 3.00 | 1.00 | | 20 | Ammonia | 0.20 | | | 2 | Acetaldehyde | 0.01 | | | 21 | Nitrogen oxides | 0.15 | | | 3 | Xylene | 0.30 | | | (converted to NO₂) | | | | 4 | Sulfur dioxide | 0.50 | 0.15 | | 22 | Arsenic compounds | | 0.003 | | 5 | Carbon disulfide | 0.04 | | | (converted to As) | | | | 6 | Phosphorus pentoxide | 0.15 | 0.05 | | 23 | Trichlorfon | 0.10 | | | 7 | Acrylonitrile | | 0.05 | | 24 | Phenols | 0.02 | | | 8 | Acrolein | 0.10 | | | 25 | Hydrogen sulfide | 0.01 | | | 9 | Propane | 0.80 | | | 26 | Sulfuric acid | 0.30 | 0.10 | | 10 | Methyl parathion | 0.01 | | | 27 | *** | 0.01 | | | (Methyl E605) | | | | 28 | Lead and its inorganic compounds | | 0.0007 | | 11 | Methanol | 3.00 | 1.00 | | | (converted to PB) | | | | 12 | Formaldehyde | 0.05 | | | 13 | Mercury | | 0.0003 | | 29 | Chlorine | 0.10 | 0.03 | | 14 | Pyridine | 0.08 | | | 30 | Chloroprene | 0.10 | | | 15 | Benzene | 2.40 | 0.80 | | 31 | Hydrogen chloride | 0.05 | 0.015 | | 16 | Styrene | 0.01 | | | 32 | Chromium (hexavalent) | 0.0015 | | | 17 | Aniline | 0.10 | 0.03 | | 33 | Manganese and its compounds | | 0.01 | | 18 | Epichlorohydrin | 0.20 | | | (converted to MnO₂) | | | | 19 | Fluorides | 0.02 | 0.007 | | 34 | Suspended dust | 0.50 | 0.15 | | (converted to F) | 3 | | | | | | | ---------------------------------------------------------------------------------------------------- Note: (1) The maximum allowable concentration for one-time measurements refers to the highest permissible value obtained from any single measurement. (2) The daily average maximum allowable concentration refers to the maximum permissible value of the average concentration on any given day. (3) The testing methods for the various hazardous substances listed in this table shall be carried out in accordance with the current \"Methods for Air Monitoring and Testing\" approved by the Ministry of Health. (4) The natural sedimentation amount of dust can be increased by 3–5 tons per square kilometer per month, based on the measured values from local clean areas. Article 12: When designing industrial enterprises that generate harmful industrial waste gases, efforts should be made to reform the production processes so as to reduce or eliminate the generation of such gases ； For harmful exhaust gases that still need to be released outside, effective measures such as exhaust gas recovery, comprehensive utilization, and purification should be employed. And in accordance with the characteristics of local planning and natural conditions, after dispersion and dilution in the atmosphere, the maximum allowable concentration of harmful substances in the air of residential areas shall not exceed the values specified in Table 1. Article 13: A certain sanitary protection distance shall be established between industrial enterprises that generate harmful factors and residential areas. The width of the health protection zone shall be determined by the construction authorities in consultation with the health and environmental protection authorities of the provinces, municipalities, and autonomous regions, based on specific circumstances. No permanent residences shall be built within the health protection distance, and the area should be landscaped. Section 2: Water Supply Hygiene Article 14: The selection of water sources for domestic drinking water in industrial enterprises, the measures for protecting the hygiene of these water sources, and the quality standards shall comply with the requirements of the current \"Hygienic Standards for Domestic Drinking Water\". Article 15: When drinking water supply pipes pass through areas contaminated by toxins, or run parallel to or intersect with pipes for wastewater discharge, etc., the current \"Code for Design of Outdoor Wastewater Systems\" and \"Code for Design of Outdoor Water Supply Systems\" shall be followed. Article 16: The domestic drinking water pipelines in industrial enterprises shall not be connected to non-drinking water pipelines. In special circumstances where potable water must be used as a backup water source for production, effective measures should be taken at the connection point between the two pipelines to prevent contamination of the potable water. When the water used for production and the water intended for drinking are supplied through the same pipeline, its quality must meet the standards specified in the current \"Sanitary Standards for Drinking Water\". When supplying water to toxic production equipment, effective measures must be taken to prevent toxic substances from entering the pipelines and contaminating drinking water. Note: When town water supply is used as production water for industrial enterprises, and there is a possibility of supplying it to toxic manufacturing equipment, effective measures must also be taken to prevent toxic substances from contaminating the town water supply. Article 17: The domestic drinking water supply systems provided by industrial enterprises shall not be connected to the urban water supply system. When connection is necessary, effective measures should be taken, and approval from the local health, environmental protection, and relevant regulatory authorities must be obtained. Section 3: Sanitary Protection of Surface Water and Groundwater Article 18: When designing industrial enterprises that generate hazardous industrial wastewater, it is necessary to actively adopt effective and advanced technologies. Measures such as the comprehensive utilization of wastewater, separation of clean and polluted water streams, and recycling should be integrated into the production process. It is essential to emit as little or no hazardous wastewater as possible, in order to reduce or eliminate harmful substances in the wastewater. Harmful industrial wastewater that cannot be completely eliminated in the production process shall comply with the provisions of Article 2 of this standard. Article 19: Industrial wastewater and domestic sewage shall be equipped with proper collection systems, as well as necessary treatment and discharge systems, to prevent pollution of the environment both inside and outside the factory. When several types of industrial wastewater are mixed and produce toxic gases (such as hydrogen sulfide, hydrogen cyanide, etc.) as well as a large amount of insoluble substances, they must be treated separately before they can be discharged into the same drainage system within the facility. When industrial wastewater is discharged into urban drainage systems, it must comply with the requirements of the current \"Code for Design of Outdoor Drainage Systems\". Article 20 Industrial wastewater used for farmland irrigation shall be treated actively and utilized with caution, and must meet the requirements regarding water source hygiene protection set out in the current \"Water Quality Standards for Farmland Irrigation\" and \"Sanitary Standards for Potable Water\". When year-round utilization is not possible and discharge into surface water is necessary, the requirements of Article 21 of these standards shall be met. Article 21 Industrial wastewater and domestic sewage must undergo necessary treatment before they can be discharged into surface waters. When it is discharged into surface water, the water quality at the nearest downstream water use point shall meet the requirements of Tables 2 and 3. Note: (1) The nearest water use point refers to the point located closest downstream of the outlet: either the section 1,000 meters upstream of the centralized water intake points for towns and industrial enterprises, or the centralized water intake points for rural domestic drinking water. (2) Industrial wastewater and domestic sewage shall not be discharged within 1,000 meters upstream and 100 meters downstream of the centralized water intake points in towns and industrial enterprises. (3) The flow rate of surface water shall be calculated based on the lowest flow rate or the average hourly flow rate during the driest month of the driest year at a 95% confidence level. The wastewater is calculated based on the highest hourly flow rate at discharge. Hygienic requirements for the quality of surface water – Table 2 –―――――――――――――――――――――――――――――――――――――――――――――――――― | Parameter | Hygienic requirement | –――――――――――――――|――――――――――――――――――――――――――――――――――――――――| Suspended solids: Color, odor, taste | Industrial wastewater containing large amounts of suspended solids shall not be discharged directly into surface water; it shall not exhibit the color, abnormal odor, or unpleasant taste characteristic of industrial wastewater and domestic sewage. | Suspended solids | There shall be no noticeable oil films or foam on the water surface. | pH value | 6.5–8.5 | Biochemical oxygen demand | Not more than 3–4 mg/L (20°C over 5 days) | Dissolved oxygen | Not less than 4 mg/L (not less than 5 mg/L in fishery waters in the Northeast region) | Hazardous substances | Not exceeding the maximum allowable concentrations specified in Table 3 | Pathogens | Industrial wastewater and hospital sewage containing pathogens must be treated and thoroughly disinfected to eliminate all pathogens before they can be discharged into surface water. –―――――――――――――――――――――――――――――――――――――――――――――――――― Article 22: When industrial wastewater and domestic sewage must be discharged into surface water that cannot dilute the pollutants or where dilution is not feasible, the quality of such wastewater must meet the requirements specified in Tables 2 and 3 of Article 21 of these standards. Article 23: Wastewater from hydraulic ash discharge, slag flushing, tailings, and coal washing must be treated to meet the requirements specified in Article 21 of these standards before it can be discharged into surface waters. Article 24 To prevent pollution of groundwater sources, harmful industrial wastewater and domestic sewage shall not be discharged into seep pits or seep wells, etc. Pipes and open channels for transporting hazardous industrial wastewater must be prevented from leaking. Industrial wastewater that can release toxic gases must not be conveyed through open channels before being fed into treatment equipment. Maximum allowable concentrations of hazardous substances in surface water Table 3 – Maximum allowable concentrations of hazardous substances in surface water Table 3 | No. | Maximum allowable concentration | No. | Maximum allowable concentration | Substance name | No. | (mg/L) | No. | (mg/L) | ——|——|——|——|——|——|——|1|Acetonitrile|5.0||13|Hexachlorobenzene|0.05|||2|Acetaldehyde|0.05||14|Phosphamidon (E059)|0.03|||3|Carbon disulfide|2.0||15|Hydrazine hydrate|0.01|||4|***Benzene|0.5||16|Tetraethyl lead|Undetectable|||5|***Chlorobenzene|0.5||17|Tetrachlorobenzene|(Calculated based on chlorine demand in surface water)||6|Dichlorobenzene|0.02||18|Petroleum (including kerosene and gasoline)|0.3|||7|Butyl xanthate|0.005||19|Methyl parathion (Methyl E605)|0.02|||8|Trichlorobenzene|0.02||20|Formaldehyde|0.5|||9|Trinitrotoluene|0.5||21|Acrylonitrile|2.0|||10|Malathion (4049)|0.25||22|Acraldehyde|0.1||Based on biochemical oxygen demand in surface water|||11|Beta-lactam|||23|Parathion (E605)|0.003||Based on oxygen demand|||12|BHC|0.02||24|Dieldrin|0.08|——|——|——|——|——|——|——|Continued Table ——|No.|Maximum allowable concentration|No.|Maximum allowable concentration|Substance name|No.|(mg/L)|No.|(mg/L)|——|——|——|——|——|——|——|25|Isopropylbenzene|0.25||40|Cobalt|1.0|||26|Mercury|0.001||41|Beryllium|0.0002|||27|Pyridine|0.2||42|Selenium|0.01|||28|Vanadium|0.1||43|Chromium: Trivalent chromium|0.5|||29|Turpentine|0.2|||Chromium: Hexavalent chromium|0.05|||30|Benzene|2.5||44|Copper|0.1|||31|Styrene|0.3||45|Zinc|1.0|||32|Aniline|0.1||46|Sulfides|(Calculated based on dissolved oxygen in surface water)||33|Picric acid|0.5||47|Cyanides|0.05|——|——|——|——|——|——|——|——|34|Fluorides|1.0||48|Chlorobenzene|0.02|||35|Active chlorine|Undetectable||49|Nitrochlorobenzene|0.05|||36|Volatile phenols|0.01||50|Antimony|0.05|||37|Arsenic|0.04||51|DDT|0.2|||38|Molybdenum|0.5||52|Nickel|0.5|||39|Lead|0.1||53|Cadmium|0.01|——|——|——|——|——|——|Note: The test methods for various parameters and hazardous substances listed in Tables 2 and 3 shall be carried out in accordance with the currently approved “Methods for Monitoring and Testing Water Quality of Surface Water” issued by the Ministry of Health. Section 4 Waste Disposal Article 25 Comprehensive utilization measures should be actively adopted for the production waste generated by industrial enterprises. Any experience in comprehensive utilization must be incorporated into the process design. When utilizing hazardous industrial waste, it is necessary to prevent the creation of new pollution. When dumping or filling in waste residues, measures should be taken to prevent their dispersion, loss, and clogging of waterways, so as to avoid contaminating the atmosphere, water sources, and soil. Article 26 Soluble industrial waste containing mercury, cadmium, arsenic, hexavalent chromium, lead, cyanides, organophosphates, and other highly toxic substances must be stored in dedicated facilities equipped with waterproof and leak-proof measures; it is strictly prohibited to bury such waste underground or discharge it into surface water bodies. Chapter 3 Workshop Hygiene Section 1 Dust and Gas Prevention Article 27 For production processes and equipment that emit harmful substances, mechanization and automation should be prioritized, sealing measures should be strengthened to avoid direct handling, and ventilation measures should be implemented in conjunction with the production process. For production processes that generate dust, wet methods should be considered first. In toxic operations, low-toxicity raw materials should be used to replace high-toxicity ones. Article 28: In workshops where harmful substances are generated, the layout of the sources of these harmful substances shall meet the following requirements: (1) When production processes that emit different harmful substances are located in the same building, those that produce more toxic substances should be separated from those that produce less toxic substances. (II) The sources of harmful substances should be located downwind of the mechanical or natural ventilation in the workplace. (III) If located in a multi-story building, production processes that generate heat and harmful gases should be situated on the upper floors of the building. If it must be installed on the lower level, effective measures should be taken to prevent contamination of the air on the upper level. Article 29: Workshops that generate large amounts of dust, toxic substances, or highly corrosive media such as acids and alkalis shall be equipped with facilities for flushing the floors and walls. The workshop floor should be flat, non-slippery, and easy to clean. Surfaces that frequently have liquid on them should be impermeable and sloped toward the drainage system. Article 30: In workshops that generate highly toxic substances such as mercury and arsenic, the surfaces of their internal structures, including walls, ceilings, and floors, shall be made of materials that do not absorb these toxins. Add a protective layer if necessary for easy cleaning. Its wastewater should be incorporated into the industrial wastewater treatment system. Article 31: Tunnels that are frequently used by people shall have natural or mechanical ventilation, and pipes for toxic liquids or gases shall not be installed therein. Article 32: The concentration of harmful substances in the workshop air shall not exceed the levels specified in Table 4. Maximum permissible concentrations of harmful substances in workshop air Table 4 ———————————————————————————————————————— | | | Maximum permissible concentration | | No. | Substance name | | | | | (mg/m³) | |———|———————————————————————|—————————————| | | (1) Toxic substances | | | 1 | Carbon monoxide | 30 | | 2 | Monomethylamine | 5 | | 3 | Ethyl ether | 500 | | 4 | Acetonitrile | 3 | | 5 | Dimethylamine | 10 | | 6 | Xylene | 100 | | 7 | Dimethylformamide (skin) | 10 | | 8 | Dimethyldichlorosilane | 2 | | 9 | Sulfur dioxide | 15 | | 10 | Selenium dioxide | 0.1 | | 11 | Dichloropropanol (skin) | 5 | | 12 | Carbon disulfide (skin) | 10 | | 13 | Toluene diisocyanate | 0.2 | | 14 | Butene | 100 | | 15 | Butadiene | 100 | | 16 | Butyraldehyde | 10 | | 17 | Triethyltin chloride (skin) | 0.01 | | 18 | Arsenic trioxide and arsenic pentoxide | 0.3 | | 19 | Chromium trioxide, chromates, dichromates | 0.05 | | | (converted to CrO₃) | | | 20 | Trichlorosilane | 3 | | 21 | Caprolactam | 10 | | 22 | Phosphorus pentoxide | 1 | | 23 | Pentachlorophenol and its sodium salt | 0.3 | | 24 | Benzene hexachloride | 0.1 | | 25 | Gamma-BHC | 0.05 | | 26 | Propylene oxide | 400 | | 27 | Acrylonitrile (skin) | 2 | | 28 | Acrolein | 0.3 | | 29 | Allyl alcohol (skin) | 2 | | 30 | Toluene | 100 | | 31 | Formaldehyde | 3 | | 32 | Phosgene | 0.5 | | | Organophosphorus compounds: | | | 33 | Demeton (E509) (skin) | 0.02 | | 34 | Parathion (E605) (skin) | 0.05 | | 35 | Phorate (3911) (skin) | 0.01 | | 36 | Malathion (4049) (skin) | 2 | | 37 | Methyl demeton (methyl E059) (skin) | 0.2 | | 38 | Methyl parathion (methyl E605) (skin) | 0.1 | | 39 | Trichlorfon (Dimefox) (skin) | 1 | | 40 | Trichlorfon (skin) | 1 | | 41 | Dichlorvos (skin) | 0.3 | | 42 | Pyridine | 4 | | | Mercury and its compounds | | ——————————————————————————————————————— Continued table ——————————————————————————————————————— | | | Maximum permissible concentration | | No. | Substance name | | | | | (mg/m³) | |———|———————————————————————|—————————————| | 43 | Metallic mercury | 0.01 | | 44 | Mercuric chloride | 0.1 | | 45 | Organic mercury compounds (skin) | 0.005 | | 46 | Turpentine | 300 | | 47 | Epichlorohydrin (skin) | 1 | | 48 | Ethylene oxide | 5 | | 49 | Cyclohexanone | 50 | | 50 | Cyclohexanol | 50 | | 51 | Cyclohexane | 100 | | 52 | Benzene (skin) | 40 | | 53 | Mononitro compounds of benzene and its homologues | 5 | | | (such as nitrobenzene, etc.) (skin) | | | 54 | Dinitro and trinitro compounds of benzene and its homologues | 1 | | | (such as dinitrobenzene, trinitrotoluene, etc.) (skin) | | | 55 | Nitro- and chlorinated derivatives of benzene (mononitrochlorobenzene, | 1 | | | chloronitrobenzenes, etc.) (skin) | | | 56 | Aniline, toluidine, xylidine (skin) | 5 | | 57 | Styrene | 40 | | | Vanadium and its compounds: | | | 58 | Barium pentoxide fumes | 0.1 | | 59 | Barium pentoxide dust | 0.5 | | 60 | Ferrobarium alloy | 1 | | 61 | Caustic alkali (converted to NaOH) | 0.5 | | 62 | Hydrogen fluoride and fluorides (converted to F) | 1 | | 63 | Ammonia | 30 | | 64 | Ozone | 0.3 | | 65 | Nitrogen oxides (converted to NO₂) | 5 | | 66 | Zinc oxide | 5 | | 67 | Cadmium oxide | 0.1 | | 68 | Arsine | 0.3 | | | Lead and its compounds: | | | 69 | Lead fumes | 0.03 | | 70 | Lead dust | 0.05 | | 71 | Tetraethyllead (skin) | 0.0005 | | 72 | Lead sulfide | 0.5 | | 73 | Beryllium and its compounds | 0.0001 | | 74 | Molybdenum (soluble compounds) | 4 | | 75 | Molybdenum (insoluble compounds) | 6 | | 76 | White phosphorus | 0.03 | | 77 | Phenol (skin) | 5 | | 78 | Decalin, chlorinated naphthalene | 100 | | 79 | Hydrogen cyanide and cyanides (converted to HCN) (skin) | 0.3 | | 80 | Biphenyl-biphenyl ether | 7 | | 81 | Hydrogen sulfide | 10 | | 82 | Sulfuric acid and sulfur trioxide | 2 | | 83 | Zirconium and its compounds | 5 | ——————————————————————————————————————— Continued table ——————————————————————————————————————— | | | Maximum permissible concentration | | No. | Substance name | | | | | (mg/m³) | |———|———————————————————————|—————————————| | 84 | Manganese and its compounds (converted to MnO₂) | 0.2 | | 85 | Chlorine | 1 | | 86 | Hydrogen chloride and hydrochloric acid | 15 | | 87 | Chlorobenzene | 50 | | 88 | Chloronaphthalene and chlorobiphenyl (skin) | 1 | | 89 | Chloropicrin | 1 | | | Chlorinated hydrocarbons: | | | 90 | Dichloroethane | 25 | | 91 | Trichloroethylene | 30 | | 92 | Carbon tetrachloride (skin) | 25 | | 93 | Vinyl chloride | 30 | | 94 | Chloroprene (skin) | 2 | | 95 | Bromomethane (skin) | 1 | | 96 | Iodomethane (skin) | 1 | | 97 | Solvent gasoline | 350 | | 98 | DDT | 0.3 | | 99 | Nickel carbonyl | 0.0001 | | 100 | Tungsten and tungsten carbide | 6 | | | Esters of acetic acid: | | | 101 | Methyl acetate | 100 | | 102 | Ethyl acetate | 300 | | 103 | Propyl acetate | 300 | | 104 | Butyl acetate | 300 | | 105 | Amyl acetate | 100 | | | Alcohols: | | | 106 | Methanol | 50 | | 107 | Propanol | 200 | | 108 | Butanol | 200 | | 109 | Pentanol | 100 | | 110 | Furfural | 10 | | 111 | Phosphine | 0.3 | | | (2) Industrial dust | | | 112 | Dust containing more than 10% free silica | 2 | | | (quartz, quartzite, etc.)** | | | 113 | Asbestos dust and dust containing more than 10% asbestos | 2 | | | | | | 114 | Talc dust containing less than 10% free silica | 4 | | | | | | 115 | Cement dust containing less than 10% free silica | 6 | | | | | | 116 | Coal dust containing less than 10% free silica | 10 | | | | | | 117 | Aluminum, aluminum oxide, aluminum alloy dust | 4 | | 118 | Glass wool and slag wool dust | 5 | | 119 | Tobacco and tea dust | 3 | | 120 | Other dust*** | 10 | ——————————————————————————————————————— Note: (1) The maximum permissible concentrations listed in the table represent the values that should not be exceeded for harmful substances in the air at workers’ workplaces. The workplace refers to the place where workers stay regularly or periodically in order to observe and manage the production process, such as factories, workshops, offices, and other similar locations. (2) Substances marked with a (skin) symbol are toxic substances that can be absorbed through the skin in addition to being absorbed through the respiratory tract. (3) If workers spend only a short time in the workshop and the concentration specified in the table above cannot be achieved even after taking measures, the issue can be resolved through consultation with the health authorities at the provincial, municipal, or autonomous region level. * The maximum allowable concentration of carbon monoxide can be relaxed for short periods of operation time: for operation times of up to 1 hour, the allowable carbon monoxide concentration is 50 milligrams per cubic meter ； Within half an hour – 100 milligrams per cubic meter ； 15–20 minutes – 200 milligrams per cubic meter. When performing the operation repeatedly under the above conditions, an interval of at least 2 hours must be allowed between two operations. ＊＊For productive dusts containing more than 80% free silica, the concentration should not exceed 1 milligram per cubic meter. ＊＊＊Other dusts refer to mineral and plant/animal-based dusts with a free silica content of 10% or less, and free from toxic substances. (4) The testing methods for the various toxic substances listed in this table shall be carried out in accordance with the current \"Methods for Monitoring Workshop Air\" approved by the Ministry of Health. Article 33: Effective measures shall also be taken for the process equipment used in outdoor operations to ensure that the concentration of harmful substances at the work site meets the requirements specified in Table 4 of Article 32 of these standards. Article 34: When the vapors of several solvents (benzene and its homologs, alcohols, or acetates) or several irritating gases (sulfur trioxide and sulfur dioxide, hydrogen fluoride and its salts, etc.) are released into the air simultaneously, the total volume of air required for thorough ventilation should be calculated as the sum of the amounts of air needed to dilute each type of gas to its maximum allowable concentration. In addition to the gases and vapors of the aforementioned harmful substances, when other harmful substances are also released into the air, the ventilation volume is calculated based solely on the amount of air required for the substance that requires the most. Article 35: The inlet of the mechanical ventilation system shall be located in a place where the outdoor air is relatively clean. The intake and exhaust systems of adjacent workshops should be arranged reasonably to avoid adverse effects. Article 36: To ensure that the air in the workshop meets the requirements specified in Table 4 of these standards, the concentration of harmful gases, vapors, and dust in the air supplied to the workshop through mechanical ventilation shall not exceed 30% of the maximum allowable concentrations specified in Table 4 of these standards. Article 37: In workshops where the air contains pathogens (such as in sorting workshops for fur and worn fabrics), substances with extremely unpleasant odors (such as those generated during glue boiling), or where the concentration of harmful substances may suddenly increase, recirculated air shall not be used for heating by hot air or for air conditioning. Article 38: The air supplied to the workshop is generally delivered directly to the work area. In workshops that generate dust without releasing harmful gases, or that release harmful gases but without significant excess heat, as well as in work areas equipped with local exhaust systems, air can be supplied from above the workshop. Article 39 Exhaust systems that are prone to vapor condensation and dust accumulation, as well as those in which the mixing of substances may cause explosions, fires, or the formation of more hazardous mixtures or compounds, shall not be connected together into a single exhaust system. Article 40: Harmful substances with high concentrations emitted by local exhaust devices may be released into the atmosphere only after undergoing purification and recovery treatment to meet the requirements specified in Article 12 of these standards. Article 41: In cases where a large amount of harmful substances may be generated suddenly during production in the workshop, accident exhaust ventilation systems should be installed. The exhaust outlet of the accident ventilation system should be arranged to avoid affecting residents and pedestrians. Section 2: Protection against Heat, Cold, and Moisture Article 42: To achieve heat protection, the design of the manufacturing process should ensure that operators are kept away from heat sources, and necessary insulation and cooling measures should be taken depending on the specific conditions. Article 43: To reduce heat loss within the workshop, the placement of heat sources shall meet the following requirements: (1) They should be placed as far outside the workshop as possible. (II) When natural ventilation relying mainly on hot air pressure is used, it should be arranged as far below the skylight as possible. (III) When natural ventilation relying mainly on cross-ventilation is used, it should be located as far as possible on the downwind side of the prevailing wind direction in summer. (IV) It facilitates the implementation of various effective insulation measures for heat sources. (5) Make work locations suitable for implementing cooling measures. Article 44: Heat workshops should be equipped with skylights that provide wind protection. The skylight and side windows should be easy to open, close, and clean. Article 45: For the intake windows used for natural ventilation in summer, their lower edge shall not be higher than 1.2 meters above the ground level, so that air can flow directly toward the work area. The lower edge of the intake windows for natural ventilation in winter is generally not less than 4 meters. If it is below 4 meters, effective measures should be taken to prevent cold winds from blowing toward the work area. Article 46: Natural ventilation shall have sufficient air intake area. Auxiliary buildings in single-story factories that generate large amounts of heat, moisture, and harmful gases shall not occupy more than 30% of the total length of the factory’s exterior walls, and should not be located on the windward side of the factory. Article 47: For workshops that generate large amounts of heat or emit harmful substances, their longest side shall be used as the exterior wall in the layout plan. If all sides are enclosed by interior walls, measures should be taken to supply clean air into the room. Article 48: When the actual outdoor temperature is equal to the calculated outdoor ventilation temperature in summer, the air temperature in the working areas of the workshop shall meet the following requirements: (1) In workshops where the heat dissipation rate is less than 20 kilocalories per cubic meter per hour, the indoor temperature shall not exceed the outdoor temperature by 3°C. (II) In workshops with an hourly heat dissipation rate of 20–100 kilocalories per cubic meter, the temperature may not exceed the outdoor temperature by 5°C. (III) In workshops where the heat dissipation rate is greater than 100 kilocalories per cubic meter per hour, the temperature may not exceed the outdoor temperature by 7°C. Note: (1) The working area refers to the space within 2 meters above the ground where the work is carried out. (2) In areas where the calculated temperature outside the ventilation room is low, and it is indeed difficult to meet the air temperature requirements at the work site according to the provisions of this article, these requirements may be appropriately relaxed, but shall not exceed those specified in Table 5 of Article 49 of these standards for the work site. (3) The regulations regarding the outdoor design temperature for ventilation in summer shall be in accordance with the current Code for Design of Heating, Ventilation and Air Conditioning in Industrial Enterprises. Article 49: The summer air temperature at the working location within the workshop shall be calculated based on the temperature difference between the inside and outside of the workshop. The limit on the temperature difference between indoor and outdoor areas is determined based on the outdoor calculation temperature for ventilation during summer in various locations, and must not exceed the values specified in Table 5. Regulations on summer air temperature at work sites in workshops – Table 5 –——–－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－ | Outdoor calculated value for local summer ventilation | Temperature difference between work site and outdoors (°C) | Temperature (°C) | Maximum allowable value | ———－－－－－－－－－－－－|——－－－－－－－－－－－－－－－－－－－| | 22 and below | 10 | | | | | 23–28 | Maximum allowable values are 9, 8, 7, 6, 5, 4 respectively | | | | | 29–32 | 3 | | | | | 33 and above | 2 | ———－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－ Article 50: In certain enterprises or workshops (such as coking, open-hearth furnaces, steel rolling, etc.), where the temperature at work sites is severely restricted by conditions, and the requirements of Table 5 cannot be met even after applying general cooling measures, the limits may be relaxed further, but by no more than 2°C. At the same time, worker rest rooms should be provided near the workplace, and the temperature in these rest rooms should generally not exceed the outdoor temperature. Article 51: In special high-temperature work areas, such as the crane cabins in high-temperature workshops, the control rooms of rolling mills, and the driving cabins of coke carriages, good thermal insulation is required, and small air-conditioning units should be installed or other effective cooling measures taken. The concentration of harmful substances in indoor air shall not exceed the values specified in Table 4. Article 52: When local air supply cooling measures are used in high-temperature work areas, the wind speed of the airflow containing water mist at the work site should be controlled between 3 and 5 meters per second, and the diameter of the mist droplets should be less than 100 micrometers ； The wind speed at the work site when the airflow is free of mist should be kept between 2 and 5 meters per second for light tasks ； The weight of the load should be controlled at 5–7 meters per second. Article 53 Industrial enterprises engaged in high-temperature work shall have the equipment and facilities necessary to prepare salt-containing cooling beverages. The layout of equipment and rooms should facilitate hygiene management. Article 54: In air-conditioned workshops where temperature is the primary requirement from a process perspective (such as textile factories), when the actual outdoor temperature equals the outdoor design temperature for summer air conditioning, the air temperature inside the workshop shall not exceed the values specified in Table 6. In areas where the outdoor design temperature for ventilation in summer is above 31°C, this temperature may be increased by 1°C as specified, with the temperature remaining unchanged otherwise. Regulations for air temperature in workshops during summer – Table 6 –－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－ | Relative Humidity (%) | Air Temperature (°C) | |－－－－－－－－－－－－－－|－－－－－－－－－－－－－－－－| | 50–60 | Should not exceed 33–32 accordingly | | | | | 60–70 | Should not exceed 32–31 accordingly | | | | | 70–80 | Should not exceed 31–30 accordingly | －－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－ Note: The regulations regarding the outdoor design temperature for air conditioning in summer shall be in accordance with the current “Design Code for Heating, Ventilation, and Air Conditioning in Industrial Enterprises”. Article 55: When designing workshops with centralized heating, the winter air temperature at the working areas within such workshops shall be no lower than 15°C for light work, no lower than 12°C for medium work, and no lower than 10°C for heavy work. When each worker occupies a larger area (50–100 square meters), the temperature can be as low as 10°C for light tasks, 7°C for moderate tasks, and 5°C for heavy tasks. When the floor area allocated to each worker exceeds 100 square meters, only local heating systems are required at the work area and the rest area. Note: (1) The regulations regarding the outdoor design temperature for winter heating shall be in accordance with the current Code for Design of Heating, Ventilation and Air Conditioning in Industrial Enterprises. (2) Light-duty work refers to jobs with an energy consumption of 120 kcal/hour or less, such as instrumentation, machining, printing, knitting, etc ； Medium-demand jobs refer to those that involve an energy consumption of 120–190 kilocalories per hour, such as carpentry, sheet metal working, and welding ； Heavy labor refers to types of work that involve an energy consumption of 190–250 kcal per hour, such as large-scale indoor packaging and manual transportation. Article 56: In areas with central heating, the indoor air temperature in auxiliary rooms during winter shall not be lower than the values specified in Table 7. Winter indoor air temperature in auxiliary rooms Table 7 ———————– | Name of auxiliary room | Indoor air temperature (°C) | | ———————– | ———————– | | Toilets and washrooms | 12 | | | | | Canteen | 14 | | | | | Offices and rest areas | 16–18 | | | | | Technical document room | 16 | | | | | Locker room | 16 | | | | | Nursing room | 20 | | | | | Shower room | 25 | | | | | Changing room for shower room | 23 | | | | | Women’s restroom | 23 | ———————– | ———————– | ———————– Article 57: In workshops where each worker has access to less than 20 cubic meters of space, it is necessary to ensure that each person receives at least 30 cubic meters of fresh air per hour ； When the occupied volume is between 20 and 40 cubic meters, it is necessary to ensure that each person receives no less than 20 cubic meters of fresh air per hour ； When the occupied volume exceeds 40 cubic meters, ventilation via air entering through doors and windows is permitted. In workshops equipped with air conditioning, at least 30 cubic meters of fresh air per person per hour must be ensured. Article 58: In areas where the outdoor design temperature for winter heating is –20°C or lower, in order to prevent the workshop doors from being exposed to cold air due to prolonged or frequent opening, entrance vestibules, external rooms, or hot air curtains should be installed as appropriate depending on the specific circumstances. Article 59: When designing heat air heating systems, it is necessary to prevent strong air currents from having an adverse effect on people; the wind speed should generally be between 0.3 meters per second and 0.1 meters per second, and the maximum temperature of the blown air should generally not exceed 70°C. Article 60: In workshops that use a large amount of water during production or generate significant amounts of moisture, necessary drainage and moisture prevention facilities should be installed during design to prevent water dripping from the ceiling and water accumulation on the floor. Article 61: The enclosure structure of the workshop shall prevent rainwater from seeping in. The inner surface of the enclosure structure in the heating workshop should be protected from condensation vapor. Note: The enclosure structure does not include doors and windows. Except in cases where process requirements permit water vapor to condense on the walls in specially humid workshops. Chapter 4 Auxiliary Rooms Section 1 General Provisions Article 62 Industrial enterprises shall, in accordance with the characteristics of production, actual needs, and the principle of convenience of use, establish rooms for production hygiene (bathrooms, cloakrooms, washrooms, laundries), rooms for daily life (rest rooms, canteens, toilets), as well as rooms for women’s and children’s health and medical facilities. Article 63: The location of auxiliary rooms should be such that it is free from the impact of harmful substances, pathogens, high temperatures, and other adverse factors. The interior structure of the building should be easy to clean, and the sanitary fixtures should be user-friendly. Article 64: The designed capacity for bathrooms, washrooms, and toilets is generally calculated as 93% of the total number of workers in the largest shift. The number of people for which the design of the locker room is calculated should be based on the total number of workers registered in the workshop. Section 2: Rooms for Production Hygiene Article 65: The layout of bathrooms, clothing storage rooms, and washrooms shall be determined on a hierarchical basis according to the hygiene characteristics of the workshop, with such hierarchy in accordance with the provisions of Table 8. Classification of Workshop Hygiene Characteristics Table 8 ———-| Hygiene | Level 1 | Level 2 | Level 3 | Level 4 | | Characteristics | | | | |——|——|——|——|——| | Toxic | Highly absorbable through the skin | Easily absorbable through the skin | Other toxins | No exposure to toxic substances | | Substances that can cause poisoning or have an unpleasant odor | Substances or dusts that do not cause contamination | Toxic substances (such as organic substances, or highly toxic substances such as trinitrotoluene, acrylonitrile, pyridine, phenol, etc.) | Cold processing, mechanical processing, etc. | ——|——|——|——|——| | Dust | Severe contamination of the entire body | Ordinary dust | Dust that may irritate the skin (such as cotton dust) | Dusts that cause contamination (such as carbon black, glass wool, etc.) | | Other | Handling of infectious materials; high-temperature work, underground work; heavy labor; handling of animal materials (such as fur, etc.) | ———|——|——|——|——| Note: Toxic substances that are easily volatile but still readily absorbed through the skin (such as benzene) can be classified as Level 3. Article 66 Bathrooms: Workshops with hygiene ratings of Level 1 or Level 2 shall be equipped with workshop bathrooms ； Grade 3 should have centralized bathrooms located near the workshop or within the factory premises ； At Level 4, centralized bathrooms can be installed in the factory area or residential area. At work sites or workshops where chemical burns may occur due to production accidents, as well as acute poisoning resulting from skin absorption, accident showers must be installed, along with water supply systems that ensure a continuous flow of water. Article 67: The number of showerheads shall be calculated according to the designed number of users, as specified in Table 9. Number of users per shower Table 9 –－－－－－－－－－－－－－－－－－－－－－－－－－－－ | Level of workshop hygiene | Number of users per shower | |－－－－－－－－－－－－｜－－－－－－－－－－－－－｜ | 1 | 3–4 | | | | | 2 | 5–8 | | | | | 3 | 9–12 | | | | | 4 | 13–24 | －－－－－－－－－－－－－－－－－－－－－－－－－－－－ Note: (1) Bathtubs are not allowed in women’s bathrooms and in workshop bathrooms with hygiene levels 1 and 2. (2) For those in the hot regions of the south who need to bathe daily, the number of people that can use each shower in the bathrooms of Grade 4 sanitary facilities can be calculated as 13 persons. (3) For facilities with heavy workloads, some bathtubs can be installed; 1.5 showers can be allocated per square meter of bath area. When the number of showers is less than 5, 1 shower can be assigned per square meter of bath area. (4) In a shower room, one sink is generally provided for every 4–6 showers. Article 68: Lockers – In lockers classified as Grade 1 in terms of workshop hygiene standards, casual clothes and work clothes should be stored in separate areas. The workwear room should have good ventilation. In a locker room rated at Level 2 for workshop hygiene, casual clothes and work clothes can be stored separately in the same room to prevent work clothes from contaminating casual clothes. A locker room with Workshop Hygiene Level 3, where casual clothes and work clothes are stored together. The coat room can be combined with the lounge. Clothing storage rooms with a workshop hygiene rating of level 4; these storage rooms can be combined with rest areas, or work uniforms can be stored at appropriate locations within the workshop. In low-temperature heavy-duty tasks with high temperatures, such as those in cold storage and underground environments, a workwear drying room should be provided. Article 69: A lavatory or washing facilities shall be provided in the workshop. The number of washbasin faucets shall be calculated in accordance with Table 10, based on the designed number of people. Article 70: In workshops where work uniforms become contaminated with pathogens or highly toxic substances that can be absorbed through the skin, or where the uniforms are severely polluted as a result of production activities, laundry facilities should be provided. Number of users per sink – Table 10 –－－－－－－－－－－－－－－－－－－－－－－－－－－－ | Workshop hygiene level | Number of users per sink | |－－－－－－－－－－－－｜－－－－－－－－－－－－－｜ | 1, 2 | 20–30 | | | | | 3, 4 | 31–40 | －－－－－－－－－－－－－－－－－－－－－－－－－－－－ Note: In workshops where there is contact with oil, hot water can be provided if conditions permit. Section 3: Rooms for Daily Hygiene Article 71: Industrial enterprises shall provide rest rooms in accordance with the characteristics of production and actual needs. The lounge can also be used for studying, warming up, dining, and smoking. In enterprises with a large number of female workers, maternity rest rooms should be provided in a clean and quiet area near the workshops. Article 72: The location of the cafeteria should be appropriate; it generally should not be too far away from the workshops, but it must not be located next to toxic workshops, and exposure to harmful factors should be avoided. The cafeteria should be equipped with washing hands, washing dishes, and heating food facilities. The kitchen should be arranged to prevent cross-contamination between raw and cooked foods, and it must have good ventilation, exhaust systems, as well as measures to protect against dust, flies, and rats. Article 73: The distance between the toilet and the work area should not be too great, and measures should be in place to remove odors and prevent flies. The toilets in the workshop are generally flush-type. The number of squatting positions in the toilets should be designed based on the number of users. In male restrooms with 100 people or fewer, one squatting toilet is provided for every 25 people ； For every additional 50 people beyond 100, one more squatting spot is added. In female restrooms with 100 people or fewer, one squatting toilet is provided for every 20 people ； For more than 100 people, one additional squatting spot is provided for every 35 additional people. In men’s toilets, for every toilet bowl, there should be a urinal provided as well (or a urinal trough 0.4 meters long). A sink should be provided in a flush toilet. Section 4: Facilities for Women’s and Children’s Health Article 74: Women’s Health Rooms Industrial enterprises with 100 or more female workers in a single shift shall have women’s health rooms, which must not be combined with other facilities. The women’s workers’ health clinic consists of a waiting room and a treatment room. The waiting area should be equipped with handwashing facilities and sinks. A temperature-controlled water tank and a washer should be installed in the processing room. The number of rinsers should be calculated based on the designed number of people. For a maximum number of female workers ranging from 100 to 200, one unit should be provided; for numbers exceeding 200, an additional unit should be added for every 200 additional workers. In industrial enterprises where the maximum number of female workers ranges from under 100 to over 40, simple water heating tanks and washers are also installed in line with the principle of thrift. Article 75: Baby Nurseries Industrial enterprises with 100 or more female employees shall establish baby nurseries, and the number of beds in such nurseries should be calculated at 10–15% of the maximum number of female workers on shift. A nursery should consist of the following rooms: a infants’ living room, a breastfeeding room, a kitchen (with a milk preparation area), a washroom, an isolation observation room, and staff offices. Small nursery rooms with 50 or fewer beds can be simplified appropriately. The usable area of the infant care room should be calculated at 2.5 square meters per bed, and a wooden floor can be used. The location of the nursery for infants should be near workshops with a large number of female workers, but it must not be situated downwind of workshops that emit harmful substances. Buildings should ensure adequate sunlight and good ventilation, as well as areas for outdoor activities. Section 5 Medical and Health Institutions Article 76 Industrial enterprises with fewer than 300 employees may establish a health clinic as required by their production needs. Its usable area should not exceed 20 square meters. Article 77: Industrial enterprises with 300 to 5,000 employees shall establish a factory or mine health clinic. Room composition and area: 1. For health clinics in factories and mines with 300 to 1,000 employees, there should be waiting and examination rooms, treatment rooms, a pharmacy, etc. Its usable area is generally 30 to 70 square meters. II. Hospitals and clinics in factories and mines with 1,000 to 2,000 employees should be equipped with waiting and examination rooms, treatment rooms, clinical and industrial hygiene laboratories, a pharmacy, etc. Its usable area is generally 70 to 110 square meters. III. Hospitals and health centers in factories and mines with 2,000 to 3,500 employees should be equipped with waiting and examination rooms, treatment rooms, clinical and industrial hygiene laboratories, X-ray rooms, pharmacies, etc. Its usable area is generally 110 to 150 square meters. IV. Hospitals and clinics in factories and mines with 3,501 to 5,000 employees should be equipped with waiting and examination rooms, treatment rooms, clinical and industrial hygiene laboratories, X-ray rooms, pharmacies, etc. Its usable area is generally 140 to 190 square meters. Note: The health clinic in factories and mines may set up several simple hospital beds as needed. Each simple hospital bed is calculated based on a usable area of 5 square meters. Article 78 General industrial enterprises with 5,000 or more employees shall establish employee hospitals ； In mountainous and remote areas with poor transportation, as well as in industrial enterprises that cause significant pollution and have 3,000 or more employees, employee hospitals can be established. Industrial enterprises that have employee hospitals should also establish factory and mine health clinics as needed. Adjacent industrial enterprises in the same area must jointly establish staff hospitals or factory health clinics, to be built with funds contributed by the participating industrial enterprises. The standards regarding the land area, building area, and number of beds in staff hospitals shall be in accordance with the \"Building Standards for General Hospitals\" issued by the Construction Commission and the Ministry of Health. Article 79: Industrial enterprises with 2,000 or more employees shall also establish workshop health stations in workshops with 500 or more employees (or where there is significant toxicity due to 300 or more employees). The workshop hygiene station can be set up in each workshop depending on the circumstances, or it can be established jointly by several workshops. Workshops located near employee hospitals or factory/mine health clinics may not need to be established. The appropriate usable area for a workshop hygiene station is generally 20 square meters. Article 80: Hospitals for workers in factories and mines shall have a department for the prevention and control of occupational diseases (including an industrial hygiene laboratory), with the usable area of such rooms generally ranging from 40 to 80 square meters. For large industrial enterprises with 10,000 or more employees, the usable area for facilities related to the prevention and control of occupational diseases and health and epidemic prevention can be increased appropriately as needed. Appendix 1: Explanation by the Ministry of Health regarding the revision of the “Health Standards for Industrial Enterprise Design (TJ36–79)”. These standards were revised in accordance with Notice No. 150 issued by the Basic Construction Committee in 1971; our ministry entrusted the Chinese Academy of Medical Sciences, together with organizations in the fields of health, design, scientific research, and medical education, to carry out this revision of the national standard GBJ 1–62 on Health Standards for Industrial Enterprise Design, which had been issued by the Planning Commission and the Ministry of Health in 1962. During the revision of this standard, the health work principle of \"prevention first\" was implemented. Building on China’s existing foundations and taking into account economic and technological development, in-depth practical investigations were conducted, experiences gained since the founding of the country were summarized, relevant research findings were incorporated, and extensive opinions were sought. Multiple specialized discussions were held on some of the key issues. Finally, it will be reviewed and finalized in conjunction with the relevant departments. The revised standard consists of four chapters, 80 articles, and an appendix. The main revisions include: expanding the scope of application ； Added the basic principles for the comprehensive utilization and treatment of \"three wastes\" ； The items and values for the maximum allowable concentrations of hazardous substances in air, surface water, and workshop air have been expanded and revised ； The space allocated to traditional Chinese medicine, as well as to facilities for the prevention and treatment of occupational diseases, has been appropriately increased, and the number of beds in the employee hospital has been specified ； The specific classifications for \"water source categories\", \"chimney heights of thermal power plants and industrial boilers\", and health protection distances in the original standard have been removed. Furthermore, the arrangement of each chapter emphasizes health requirements. During the implementation process, all relevant units are requested to keep summarizing their experience. If any modifications or additions are needed, please send your suggestions and relevant materials to the Institute of Health of the Chinese Academy of Medical Sciences, with a copy sent to our department, so that further revisions can be made in the future.

The specified value after passing through the dust collector is 50mg/m3

Hygienic standards for the design of industrial enterprises: The original standard TJ36—79 has been replaced by standard GBZ 1-2002; in case of any discrepancies, the provisions of standard GBZ 1-2002 shall prevail. See also (GBZ 2-2002) Occupational exposure limits for hazardous factors in the workplace