[tips] What are the classification of respiratory protection products?

1 Introduction

Respiratory protective equipment is personal protective equipment that prevents harm to the human body when oxygen-deficient air and toxic and hazardous substances are inhaled into the respiratory organs. In production, daily life and certain extreme occasions, the use of respiratory protection products to avoid or reduce the harm of toxic and hazardous substances in the environment through the respiratory organs to the human body is increasingly receiving attention and attention.

2. There are many ways to classify respiratory protection products, which can be summarized as follows.

2.1 Classification according to protective principle

It is mainly divided into filter type and isolation type.

Filter-based respiratory protection products are based on the principle of filtration and absorption, using filtering materials to filter out toxic and harmful substances in the air, and convert contaminated air into clean air for people to breathe. Such as dust masks, gas masks and filter gas masks.

Isolated respiratory protective equipment is based on the principle of isolation, so that the human respiratory organs, eyes and face are isolated from the external polluted air, relying on its own air source or air pipes to introduce clean air outside the contaminated environment as the gas source, Respiratory protective equipment that protects the normal breathing of personnel is also called an insulated gas mask. Such as oxygen-type gas masks, oxygen-type gas masks, long tube respirator and diving masks.

The use of filter-type respiratory protection products is subject to environmental restrictions. When there are toxic and hazardous substances in the environment that cannot be filtered out by the filter material, or when the oxygen content is 18% lower, or when the concentration of toxic substances is high (>1%), it cannot be used. This type of environment should use isolated respiratory protection products.

2.2 Classified by gas supply principle and gas supply method

It can be divided into three categories: self-priming, self-contained, and powered air supply.

Self-priming respiratory protection products refer to respiratory protection products that rely on the wearer’s spontaneous breathing to overcome resistance of parts, such as ordinary dust masks, respirator masks and filter-type gas masks. It is characterized by its simple structure, light weight, and no need of power consumption. The disadvantage is that due to the formation of negative pressure in the space between the protective equipment and the respiratory organs during inhalation, the airtightness and safety are relatively poor.

Self-contained respiratory protective equipment refers to respiratory protective equipment that uses compressed gas cylinders as a source of gas to ensure normal breathing for personnel, such as gas masks and oxygen masks. Its characteristic is that compressed gas cylinders are used as gas sources. They are not limited by the type and concentration of poisons in the external environment during use. However, they are heavy, have complicated structures, and are inconvenient to use and maintain. They also have high costs.

Powered-air respiratory protection products refer to respiratory protection products that rely on power to overcome component resistance, provide air supply, and ensure normal breathing for personnel, such as military filtering air-supply masks and air-breathing long-tube respirator. Its characteristic is to overcome the resistance of inhalation through the power, and the physical load of the personnel in use is small, and it is suitable for use in environments and occasions such as large operating intensity, low atmospheric pressure (such as the plateau), and critical situations and psychological stress of personnel.

2.3 According to the protective location and the connection of air source and respiratory organ

It is mainly divided into three types: mask type, oral type and mask type.

Mask-type respiratory protection products mainly refer to respiratory protection products that can harm humans by inhaling toxic and hazardous substances by protecting the mouth and nose of respiratory organs, including planar, semi-stereoscopic, and stereoscopic types, such as ordinary medical masks, and Dust masks and gas masks.

Mask-type respiratory protection products protect the respiratory organs, but also protect the eyes and face, such as various filter-type and isolated gas masks.

Oral breathing apparatus is also commonly referred to as an oral respirator. The difference between the two types is that, when wearing such respiratory protective equipment, the nose should be clamped with a nose clip and must be used to breathe. The air is polluted by the outside. Filtered directly into the mouth. It is characterized by its simple structure, small size, light weight, and good airtightness, but it can't speak and talk when used. Can be used for mine self-rescue, emergency escape and other situations and occasions.

2.4 According to personnel breathing environment classification

Can be divided into two types of positive pressure and negative pressure.

The positive pressure type refers to the respiratory protective equipment in which the pressure in the mask during the respiratory cycle is greater than the ambient pressure during use; the negative pressure refers to the respiratory protection during the respiratory cycle in use and the pressure in the mask is less than the ambient pressure during the inhalation phase. Supplies. Isolated and powered air-type respiratory protective products are mostly supplied by cylinders or dedicated gas supply systems, which are generally positive pressure; filter-type respiratory protective products mostly rely on spontaneous breathing, and are generally negative pressure type. Positive-pressure respiratory protection products can prevent the leakage of externally polluted or oxygen-deficient air, and have higher protection safety. When the external environment is highly dangerous, it should generally be preferred.

2.5 According to the use of object classification, can be divided into two major military and civilian categories.

2.6 other classification methods, according to the air source carrying methods, can be divided into two types of air-carrying and long tube. In addition, it can be divided according to the applicable fields and occasions, and can be divided into industrial masks, fire masks, emergency escape masks, and diving masks.

3. Several common respiratory protection products

Here are some common respiratory protection products.

3.1 Filter Respiratory Protection Products

(1) Dust masks

It is a filter type respiratory protection product with gauze, non-woven fabric, and ultra-fine fiber materials as the core filter material. It is used to filter out toxic and harmful substances in the air, but it has no protective effect on toxic and harmful gases and vapors. Among them, ordinary dust masks that do not contain ultra-fine fiber materials only have the function of protecting large particles of dust, and are generally reusable after being cleaned and disinfected; dust-proof masks containing ultra-fine fiber materials can protect large particles of dust. , It can also protect various toxic and harmful aerosols with finer particle sizes. The protective and protective effects are better than ordinary dust masks. Such masks are generally not reusable, and are mostly disposable products, which require regular replacement of filter cotton. .

It is applicable to the environment where the pollutants are only non-volatile particulate matter and do not contain toxic and harmful gases and vapors.

Figure 1 self-inhalation filter type particulate respirator (commonly known as dust masks)

(2) Respirator masks

It is a filter-type respiratory protection product that uses ultra-fine fiber materials, activated carbon, and activated carbon fiber as the core filter material. The microfiber material is used to filter particulate matter in the air, including toxic and harmful aerosols, activated carbon, activated carbon fibers and other adsorbent materials for filtering toxic and harmful vapors and gases. Compared with dust masks, gas masks can not only remove large particles of dust and aerosols in the air, but also have a certain filtering effect on toxic and harmful gases and vapors.

It is applicable to the environment where work or workplaces contain relatively low concentrations of toxic and harmful vapors and gases, and may contain particles of toxic and harmful substances (including aerosols).

(3) Filter gas mask

It is also a filter type respiratory protection product that uses ultrafine fiber materials, activated carbon, and activated carbon fibers as the core filter material. Its composition mainly includes masks and filter parts. Compared with gas masks, filter gas masks and gas masks have similar protective functions. They can not only protect large particles of dust and aerosols, but also protect toxic and harmful vapors and gases. Their difference lies in the fact that filter-type gas masks filter out toxic and harmful gases, have a wider range of vapor concentration, and have longer protection time, so they are safer and more reliable. In addition, from the consideration of protective parts, it can protect the respiratory organs (mouth, nose), but also can protect the eyes and facial skin from direct damage of toxic and harmful substances, and generally better sealing effect, with higher and more comprehensive Protective effectiveness.

Applicable to chemical industry, petroleum industry, military, mining, warehouse, seaport, scientific research institutions and other fields and occasions.

Figure 2 Self-priming filter gas mask (commonly known as gas mask)

3.2 Isolated Respiratory Protection Products

(1) Oxygen breathing apparatus

Also known as oxygen gas masks, compressed gas cylinders are the source of gas. The gas contained in the cylinders is compressed oxygen. According to whether the exhaled gas is discharged to the outside world, it can be divided into two categories of open-circuit and closed-circuit oxygen respirator. The exhaled breath of the former is discharged directly to the outside through the breather valve. Considering the safety reasons, it is rarely used.

Oxygen breathing apparatus work time is generally 60 ~ 240min, the type of respirator is different, the maximum limit of protection time is also different.

Oxygen breathing apparatus is commonly used respiratory protection equipment when personnel work in severe environment, presence of interstitial gas, unclear type of toxic gas, or lack of oxygen.

(2) Air breathing apparatus

Also known as gas masks, sometimes called fire masks. It uses a compressed gas cylinder as a source of gas, but the gas contained in the cylinder is compressed air. According to the pressure between the mask during the breathing process and the ambient pressure, it can be divided into positive pressure and negative pressure. The positive pressure type maintains positive pressure in the mask during use, which is safer. The latter has basically replaced the latter and is widely used.

Air respirator working time is generally 30 ~ 360min, depending on the type of respirator, the maximum limit of protection time is different. In general, air respirator protection is slightly shorter than oxygen respirator.

Air respirator is mainly used by fire fighters and related personnel to conduct fire source reconnaissance, fire extinguishing, disaster relief, emergency rescue and support in the handling of fire, hazardous material leakage, smoke, and lack of oxygen. In addition, it can also be used in heavy industries, shipping, civil aviation, water plants and sewage treatment stations, oil and gas exploration and procurement, petrochemical industry, petroleum refining, chemical products, environmental protection, military and other fields and occasions.

(3) Oxygen breathing apparatus

Also called oxygen-type gas mask, it is a kind of closed-circuit circulation that uses the oxygen dioxide breakage and water vapor in the exhaled breath of a person to react with an oxygen generating agent containing a large amount of oxygen to generate oxygen, so that the expired gas is supplemented with oxygen and purified and then used for breathing by personnel. Respirator.

Oxygen breathing apparatus work time is generally 30 ~ 60min, shorter than oxygen breathing apparatus and air breathing apparatus.

The application occasions of oxygen breathing apparatus include: fire protection, mine rescue, and gas leakage accident treatment.

3.3 Other types of respiratory protection products

(1) Emergency escape breathing apparatus

It is specifically designed for emergency escape, including special fire escape masks and isolated escape ventilators that can be used in a variety of critical situations.

Fire escape masks are filter-type respiratory protection products. Besides filtering dust, aerosols and general harmful gas vapors, they also have the function of filtering out carbon monoxide.

Inspiratory escape ventilators generally use compressed air cylinders as the source of air. Similar to air respirators, there are certain differences in design and protection time. This type of respirator mainly has the following characteristics: 1 Lightweight and easy to wear; 2 The effective use time is generally 10~15min, which can ensure enough escape time, while the weight of the equipment is lighter; 3 The visual effect is obvious, the color is bright or with There is a light-emitting substance that can be found easily.

(2) Long tube respirator

The most prominent feature is its long air duct (50~90m), which can be used in conjunction with mobile air supply, mobile air purification stations, etc., mainly using compressed air cylinders as the air source, and some using filtered air as the air source. .

Suitable for long-term operation in complex fire rescue and a wide range of chemical, biochemical and industrial pollution environments.

(3) Powered air respirator

This type of respiratory protection product mainly uses the principle of combining power supply air and gas filtration to provide users with air supply. The advantage is that it can reduce the resistance of exhalation and at the same time it can form a certain positive pressure in the mask to improve the comfort of use and the safety of protection. Children's masks, wounded masks and masks used on the plateau generally belong to this type of mask.