Labor hygiene personal protective equipment

Personal protective equipment is a primary prevention in the three levels of prevention in the comprehensive measures to prevent occupational harmful factors. When the occupational harmful factors cannot be improved from the equipment for prevention, it is also the main protection means for protecting health. Personal protective equipment includes protective caps, protective clothing, protective glasses and face masks, respiratory protection devices, noise protection appliances, and skin protection products. The selection of personal protective equipment should pay attention to its protective characteristics and benefits, and it should be strengthened in training, management and maintenance in order to ensure that it is often effective.

1 protective cap

US MSA Methian GALLET F2 European protective cap

The protective cap is used to prevent accidental heavy objects from falling or flying to damage the head and prevent the pollution of harmful substances, etc. The safety protective cap was made of compressed leather, cloth bakelite, rattan, wicker, etc. in the past. At present, synthetic resins are used for modification. Polyethylene and polystyrene resins, polycarbonate, glass fiber reinforced resin, etc. China has such a protective cap to the national standard (GB2811 - 81), the cap content requires weight not exceeding 400g, the brim 10 ~ 35mm, an inclination of 45 ° ~ 60 °, the bill 10 ~ 50mm, the cap color for the light Conspicuous colors and technical tests requiring shock absorption, penetration resistance, low temperature resistance, flame resistance, electrical insulation, and lateral rigidity are sometimes used, such as safety helmets for welders.

The general pollution prevention labor protection cap is a cap made of cotton cloth or synthetic fiber.

2 protective clothing

There are mainly anti-static and chemical contaminants that can damage the skin or enter the body through the skin.

2.1 Antistatic Protective Clothing

Anti-static protective clothing

2.1.1 Main content

Suitable for durable antistatic clothing worn in fire and explosion hazardous locations.

2.1.2 Terms

1. Anti-static work clothes: Work clothes made of anti-static fabrics for the purpose of preventing static electricity from accumulating.

2. Anti-static fabric: In order to prevent static electricity from accumulating in the clothing, the textiles are mixed with conductive fibers or anti-static synthetic fibers or mixed interwoven fabrics at equal intervals or evenly.

3. Conductive fiber: The collective name for a fiber made entirely or partially of a conductive material or a sub-conducting material using a metal or organic material.

2.1.3 Precautions

1. The style of anti-static clothing: The overall work clothes are “three tight” and the bottoms are straight pants.

2. Metal accessories must not be used on clothing and must be used ( buttons, zippers, etc. ) . It should be ensured that metal accessories are not exposed directly when worn.

3. All anti-static fabrics should be used in clothing and no lining should be used. Must be used liner (pocket, reinforced cloth, etc.), inner liner the exposed surface area accounted for all anti-static clothing exposed area of 20% or less; more than 20% (e.g., special winter clothes or clothing), and the liner should be made of the mask to be Demolition.

4. The products produced by the production plant must be subject to the inspection of the quality supervision department of the protective products designated by the state, and the product production license and product certification must be obtained before production and sales.

5. The product must be inspected by the manufacturer after passing the inspection, together with the product certificate, the instruction manual and the inspection and verification issued by the quality supervision department of the protective product specified by the country.

6. The distribution unit shall sell the products that have the certificate of “quality inspection of protective products designated by the state”. The use unit must purchase the product with product certification, and shall use the products after acceptance by the safety technical department.

7. Each finished product must be marked with the manufacturer's name ( or factory record ) , product name, trademark, model specification, and production date.

8. For the zone classification of hazardous locations for gas explosion, see Appendix D ( Reference ) . If it belongs to zone 0 or zone 1 , and the combustible energy is less than 0.25mJ , wear antistatic clothing.

9. It is forbidden to wear in flammable and explosive places.

10. It is forbidden to attach or wear any metal objects on antistatic clothing.

2.2 Clothing for Protection of Chemical Contaminants

Chemical protective clothing

Anti-acid and alkali-proof garments are often made of polypropylene, polyester, or Kleenex fabrics, because of better acid and alkali resistance; the protective clothing used in oil refining operations is usually grafted with fluoromonomer ( that is, the nature of the main chain is different from that of the main chain) . branched-chain) of synthetic fabric production, due to the formation of polymer macromolecules fence surface of the fabric, skin oil pollution can be prevented, and the air may freely pass. Protective garments that prevent the permeation of chemicals into the body are generally made of polymers that are impermeable or have low permeability to the chemicals they are protecting, and are coated on chemical fiber or natural fiber fabrics. However, all chemical protective clothing is not conducive to evaporative heat dissipation, so that the skin temperature and humidity increase, can increase the permeability of the skin, chemical protective clothing without the expected test, must be observed after wearing, such as skin discoloration, a sense of tension, whether Chemical smells, etc. Due to differences in manufacturing processes or the use of raw materials and additives, protective clothing provided by different manufacturers may have different levels of protection. Workers engaged in flammable and explosive materials should not wear overalls of chemical fiber fabrics because in the event of a fire, the high temperatures at the time of burning will cause the chemical fiber to melt and adhere to the human skin, causing serious burns. To perform different jobs, choose different colors. Only workers exposed to tetraethyl lead should wear white protective clothing. Because tetraethyl lead is red, it is easy to detect contamination.

3 protective glasses and masks

The main protection of the eyes and face from electromagnetic radiation ( ultraviolet, infrared and microwave, etc. ) radiation, dust, smoke, metal and gravel debris and chemical solution sputtering and other damage.

3.1 protective glasses

France GALERAS anti-fog and anti-fog protective glasses

The frame of protective glasses is usually made of plastic or rubber which is flexible and can conform to the face shape. The frame is large enough to cover the glasses worn by the user. Protective lenses can be divided into two categories based on their principle of action.

3.1.1 Reflective Protective Lenses Apply bright metallic films, such as chromium, nickel, to glass slides.

Silver and so on. In general, the range of reflective radiation ( including microwaves, infrared rays, ultraviolet rays, etc. ) is wide and the reflectance can reach 95 %.

3.1.2 Absorptive Protective Lenses are mostly coloured and made according to the principle of selective absorption. For example, a green glass absorbs red and blue light and passes only green light. However, in some production operations, both short-wavelength and long-wave radiation exist, and glass plates that can absorb the color effect cannot be used. Instead, a certain amount of chemical substances such as ferrous oxide can be added to the glass to absorb radiation more completely. line.

3.2 Mask

GRS Fire Control Hood

3.2.1 Face masks for protection against solid dust and chemicals splashed into the eyes and damaged face Manufactured from lightweight transparent plastic, polycarbonate and other plastics are now used. The structure is improved compared to the previous ones. The cover is on both sides and the lower end, respectively. The ears and the lower jaw extend towards the neck, allowing the mask to cover the face more fully and enhance the protection.

3.2.2 Heat protection masks In addition to the aluminum foil masks mentioned in the above hot clothes, they can also be made of single or double metal meshes, but double layers are preferred to allow some of the radiant heat to be blocked and dissipated in the air. If it can be chrome or nickel, it can enhance the anti-heat effect of reflection and prevent rust. Metal mesh masks also protect against microwave radiation.

3.2.3 except welders mask with dark green lens number (larger number, the smaller the radiation transmittance, see GB GB3609.1 - 83 welding goggles, which cardboard mask with constant thickness portion Made of fiber, light weight, heat resistant, and has good electrical insulation.

3.3 Respiratory Protection

GRS full face mask filter gas mask

Including dust masks, respirator masks or gas masks , there are many types, according to the structure and the principle of action, can be divided into filter ( also known as clean ) and isolated ( also known as air supply ) respiratory protection two categories, according to Its performance and use can be divided into several types.

3.3.1 Filter Respiratory Protection

The harmful substances in the air are filtered and purified, and the scope of use is checked according to the purification efficiency. The general principle is that the concentration of harmful substances in the air is not very high, and the oxygen content in the air is not less than 18 % in our country , but is generally considered not to be less than 19 %. This type of protector can be divided into mechanical filter type and chemical filter type.

3. 3.2   Mechanical filter type

It is mainly used as a dust mask when it is mainly used as a mask to prevent harmful substances such as dust, smoke or mist. The filtering and purifying effect depends on the porous filter material, which usually divides inhalation and exhalation into two channels. Good performance products can filter out fine dust, and have good ventilation and low resistance. After such masks have been used for a certain period of time, the resistance to suction will increase due to blocking of the pores of the filter material by dust, etc., and attention must be paid to the timely replacement of the filter material or the treatment of the filter material before use. Of national standards GB2626 - 81 self-absorption filter respirators, category 1, 2, 3, 4, which are the dust barrier of claim ≥ 99%, 95%, 90 % and 80%, and provides various types of masks The scope of application. With regard to wearing disposable masks, it has been reported that physiological strength is accompanied by significant physical consumption, especially in moderate- and heavy-duty labor workloads, such as heart rate, respiration, blood pressure, respiratory resistance, and inhaled and exhaled air temperature.

3. 3.3   Chemical filtration

The composition of the gas mask consists of a mask made of thin rubber, with a short snake attached to the tail, a canister attached to the tail, or one or two cartridges attached directly to the mask ( this type is also called a full face mask ) . If some of the harmful substances do not irritate the skin or mucous membranes, there is no need for a mask, as long as you use a mask ( also called a half mask ) with a storage kit . Regardless of the mask or mask, the inhalation and exhalation are separate. Mask or mask and the gap between the West, full mask to allow less than 230ml ( with oropia mask inside the hood, then less than 170ml) , half mask is less than 170ml , if too large, can be due to excessive CO2 in the void , so that the impact Inhale ingredients. Filters used to purify harmful substances in medicine jars or hoods vary depending on the object to be protected, such as sodium lime for acid mist, copper sulfate for ammonia, and iodine-containing activated carbon for mercury; activated carbon adsorbs various gases and vapors to varying degrees. effect, the adsorption effect of organic compounds in general better than inorganic compound, and generally higher adsorption of molecules containing carbon number of organic compounds, aromatic compounds and effective adsorption more aliphatic, different quality in addition activated carbon adsorption efficiency difference; " Huobu Ka "(hopcalite), a mixture of various metal-based oxides, which act as the oxidation of carbon monoxide to carbon dioxide. Activated carbon and "Hobka" filters can be regenerated using appropriate methods and reused. Most of the commonly used purification filters are 8 to 14 mesh granular materials. China's current production of canisters, various models coated with different colors of the mark, and there is a scope of protection and change the filter material time. Some filter-type respiratory protection devices are marked as not suitable for use in organic compound vapors where odors are not readily detectable and which react with the adsorbent. National standards of product filter respirators namely GB2890 - 82, GB2891.1-6 - 82, GB2892.1-12 - 82 , 19. In addition to the provisions of the filter replacement time, can be used to determine whether the air content in the mask exceeds the national maximum allowable concentration of health standards to measure the decision, recently reported that the amount of 59.1g / box of activated carbon and flow rate of 53L/min for 121 species The test of the chemical yields a 50 % breakthrough time that can be estimated using the following formula:

Logr=4.26—0.739 logC1

Where r is 50 % penetration time (min) , C1 is the concentration of harmful substances in the air ( × 10-6) 3.4.2 Isolation ( air supply ) Respirators The air ( or oxygen ) required for breathing is not purified field air but is supplied separately. According to its gas supply, it can be divided into two types: self-contained and external input. 3.4.2.1 The self-contained structure consists of a mask, a short snake connected to the mask, a gas supply regulating valve connected to the end of the tube, and a gas supply tank at the other end of the valve. The gas supply tank is fixed on the back of the worker or on the abdomen of the abdomen. The passage is isolated from the outside world. The air supply tank is made of steel or aluminum alloy. There are two types of pressure resistance. One tank contains compressed oxygen ( or air ) for inhalation, and the exhaled carbon dioxide is removed from the medicine ( sodium lime, etc. ) preset in the respiratory pathway. Inhalation, in general, a large compressed oxygen tank can be maintained for about 2 hours, there are also about 40 to 60 minutes, a small about 0.5 hours; 2 cans of peroxide and a small amount of copper salt as a catalyst, the exhaled water Vapors react with carbon dioxide to produce oxygen for inhalation. This type of protector is mainly used for emergency workers to wear when accidents occur, or in the working environment where the density is not ventilated and the concentration of harmful substances is extremely high and oxygen is lacking. Since peroxide is a severe oxidant, a self-contained breathing apparatus using peroxide as a gas source should be used to prevent the use of peroxide gas canisters when used in the presence of flammable or explosive substances. In case of loss, accidents will occur. The existing oxygen supply respiratory protection device is equipped with an emergency replenishment device. When oxygen supply is found to be insufficient, press the emergency device button with your finger to release oxygen for use within 2 to 3 minutes so that the wearer can immediately leave the site. There is also a self-contained positive pressure type air respirator. During work, its mask always maintains a pressure slightly higher than the pressure of the external environment, so that external harmful substances can not enter the hood, and is equipped with a reminder to wear the cylinder air is about to run out Alarm device.

3. 3.4 external input

The main difference between this type of protector and the self-contained type is that the gas supply source is not carried by itself but is transported from elsewhere. According to its structure, composition and use, it can be divided into two kinds.

1 Snake mask: It consists of a mask, a mask attached to a long snake tube, and a snake tube attached to the air supply control valve of the leather belt to reduce the weight of the snake tube on the mask, and the leather belt can be connected with a long rope in order to meet the situation. In the event of an accident, rescue can be done with a long rope. The leather belt is also called a safety belt. The end of the coil is connected to an oil-water dust separator, followed by a compressed air compressor or blower for air delivery. In winter, it is necessary to cool the air to add air preheater before the separation of oil and water dust to heat the input air. The snake mask with a blower or a compressor attached thereto should not exceed 50 m in length with a hand crank blower, 100 m to 200 m in compressed air , and the over-long resistance increase, and the intermediate folding may hinder the supply of gas. The application scope and main use of this snake mask is the same as that of the aforementioned self-contained air respiratory protection device, but the user's range of motion is limited by the length of the snake tube. The snake mask can also be transported without a blower or compressed air, that is, the tail of the tube is placed in a clean place near the air, and the air is input depending on the user's own suction. However, the length of the coil should be about 8m , and should not exceed 20m at most . The air resistance should not exceed 588Pa (60mmH2O) , and the expiratory resistance is less than 294Pa (30mmH2O) . It is applicable to the limited scope of work activities, and the concentration of harmful substances in the ambient air is extremely high. It is not possible to use cleansing respirators . The device cannot be used for disaster relief.

2 Air supply masks and helmets: The air supply mask is a mask that separates the inhalation and exhalation passages, and is connected with a short coil or pressure resistant rubber tube. The tube is connected to the air supply valve on the leather belt. The air-supply helmet is a special hood that covers the entire head and extends to the shoulders. It is supplied with gas from one end of the small hose into the helmet and the other end is also fixed to the air valve on the belt. It is necessary for the air-supply mask and helmet. The air for breathing can be input through a small rubber tube via an air line installed on a nearby wall. The amount of air supplied to the helmet should keep the helmet within a slight positive pressure. The applicable scope of the air-supply mask is the same as that of a snake mask without a blower. Helmets are commonly used for sandblasting, shot blasting, etc., and can also be used for coal mining operations. The input air line should also be equipped with an oil-and-water dust separator. If necessary, an air preheater can be added in winter. Two or more external input-type respirators, existing national standards for these products in our country, GB6220 - 86, called long tube mask. Its ventilation resistance, the resistance to inhalation, differs depending on the type of respiratory protection device and the inspiratory flow.

3.4 earplugs

An embolus for insertion into the external auditory canal is required to seal the external auditory canal without causing irritation or feeling of pressure. Commonly used plastic or rubber, many forms, in the past the most common who plug into the ear canal heart-shaped, there are hollow, there are solid core, with a variety of sizes. In addition, silicone rubber, which is colloidal at room temperature, is directly injected into the external auditory canal of the user. After a while, the elastic earplug is cemented. This plug fits perfectly in the ear canal of the user; it also has ultra-fine softness treatment. Fiberglass wool is used as earplugs, which are soft and contain no crude fiber impurities, but also need to be wrapped with porous plastic paper so that they are not easily scattered. Even the use of cotton yarn to make earplugs, the experimental results show that the noise attenuation of the high-frequency band noise can reach 16.25 ~ 21.27dB (A) , less attenuation of the language frequency signal, the sound insulation value of the cotton yarn earplug is 13.86dB (A) , in the noise When the strength is less than 104dB(A) , the noise can be attenuated to meet the 90dB(A) range of existing enterprises in the Hygienic Standard for Industrial Enterprise Noise . Currently marketed by the simplest effective as a plastic cylinder made of sponge, soft and flexible, inserted into the ear canal by pinching and the like bounce its own, it can be adapted to different types canal. Some studies have pointed out that earplugs have lower noise reduction capability than earcups at low frequencies. National standards earplugs are GB5893.1 - 86.

Regular plastic bowls are rectangular cups with a foam or sponge cushion covering the ears, and an elastic headband ( bow ) is attached between the two cups to hold the head tightly on the head. The earmuffs can cover part of the mastoid bone and part of the skull, helping to reduce a small part of the noise that can be transmitted through the bone to the inner ear. The existing domestically produced bow frame and cover body are connected with a directional support structure that can be positioned and rotated 360 ° so that the arch frame can be positioned on the head, under the armpit, and behind the neck. Large volume earmuffs. National standard ear products have GB5893.2 - 86. The anti-noise helmet can cover most of the skull to prevent strong noise from reaching the inner ear through air and bone conduction. The helmet on both sides of the helmet is often lined with sound-proof material to enhance the protection effect.

For the selection of anti-noise appliances, that is, the selection of earplugs, earcups, and helmets, the strength and nature of the noise in the operating environment should be considered, and the performance of various anti-noise appliances to attenuate noise should be considered. The steady-state noise, the intensity (A) in the following 110dB, and a frequency of 1000 ~ 3000Hz, the single use earplugs or earmuffs can. If the noise is too strong, earplugs and earmuffs should be used even at low frequencies ( less than 1000Hz) . It has been reported that the combined effect of noise reduction is 6 to 18dB (A) higher than that used alone , or wearing a helmet.

The information in this article comes from the Internet and was reorganized and edited by China Rescue Equipment Network.