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1 Introduction: Over the past 20 years of reform and opening up, China has achieved remarkable economic progress that has caught the world’s attention. Along with this economic growth, the quality of life for the Chinese people has also seen significant improvements, shifting from a focus on merely meeting basic needs to an emphasis on quality of life and health. Work is not only an important foundation for providing people with the basic necessities for life, but the quality of working conditions also affects everyone’s health and safety. However, the current state of occupational safety and health in our country is generally unsatisfactory. In recent years, thousands of cases of acute and chronic poisoning have been reported nationwide each year, resulting in hundreds of deaths. According to the latest statistics, in 1998, a total of 16,869 people across the country suffered from occupational diseases; of these, 10,637 were in the industrial sector (63.1%), while 6,232 suffered from pesticide poisoning (32.9%). Among industrial occupational diseases, pneumoconiosis was the most common, accounting for 72.5%, followed by acute and chronic poisonings at 18.6%. As the country with the highest incidence of pneumoconiosis in the world, 8,285 new cases of pneumoconiosis were diagnosed in 1998; by the end of that year, the total number of people suffering from pneumoconiosis nationwide had reached 542,041. However, these are only official statistics and do not include those affected by pneumoconiosis among workers in township enterprises and private businesses scattered across the country, especially in industries where pneumoconiosis is prevalent such as small coal mines, small construction material factories, and small cement plants. This is because such enterprises basically do not conduct any health checks on their workers. Since the primary route through which various health-harming pollutants present in the workplace affect the human body is the respiratory system (accounting for about 90%), individual protective measures for the respiratory system have always been one of the important methods used by countries to prevent and control occupational respiratory hazards. The standards currently in use in our country for individual respiratory protection equipment are: · · · · These standards specify the technical requirements, inspection rules, and usage guidelines for dust masks and gas masks, which have been widely applied in production and have helped to protect workers’ health to a certain extent. However, these standards are already behind those of other **, especially those in industrially developed ** and some developing **. As developed ** continue to update their regulations and standards over the years, this gap is widening further. On July 10, 1995, the latest standard for respiratory protectors, established by the U.S. National Institute for Occupational Safety and Health (NIOSH), came into effect. It represents the current standard for certifying respiratory protectors, replacing the relevant regulations set by the U.S. Mine Safety and Health Administration; it also updates the testing standards for dust filters〖2〗. On January 8, 1998, the U.S. Occupational Safety and Health Administration (OSHA) issued the latest respiratory protection standard, 29CFR1910.134, which took effect on April 8, 1998. This standard introduces some new regulations regarding respiratory protection. Below, based on a brief introduction to 29CFR1910.134 and 29CFR84, a comparative analysis is presented of the gaps in respiratory protection in China and the tasks that need to be undertaken. 2 The U.S. respiratory protection standard, 29CFR 1910.134, applies to workplaces in general industrial enterprises, the construction industry, shipyards, coastal operations, and ports. The original 29CFR1910.134 was replaced by 29CFR 1910.139, which applies only to respiratory protection for pulmonary tuberculosis. 2.1 Employer’s responsibilities Regulations clearly stipulate that it is the employer’s responsibility to protect workers’ health and safety at work. When respiratory hazards that threaten workers’ health are present in the air of the workplace, employers should first seek engineering controls, such as enclosed operations, ventilation, and replacing highly toxic materials with less toxic ones. When effective engineering controls cannot be implemented or are still in the process of being implemented, it is necessary to wear respiratory protection to safeguard workers’ health. Respiratory protection must be provided by the employer; such protection must be suitable for the nature and level of the contaminants to which protection is needed, as well as appropriate for the workers to wear. The employer must also establish and implement a respiratory protection program. 2.1.1 Respiratory Protection Program: When the concentration of air pollutants to which employees are exposed in the workplace exceeds the Permissible Exposure Limit (PEL) set by OSHA, employees must wear respiratory protection devices. Whenever respiratory protection is required, or whenever the employer requires employees to wear respiratory protection, the employer must establish a written respiratory protection plan that is tailored to the specific production processes, and implement and maintain it. The respiratory protection plan must be adjusted accordingly when changes in working conditions affect the need to wear respiratory protection. Even if the levels are not above the limits, employees still have the right to request that such protection be used. This voluntary use is appropriate when the concentration of air pollutants exceeds the maximum allowable concentration (TLV) set by the American Conference of Governmental Industrial Hygienists (ACGIH), and at the same time that TLV is lower than the PEL. When it falls under the aforementioned voluntary use scenario, the employer is not required to establish a written respiratory protection plan. 2.1.2 Contents of the respiratory protection plan The respiratory protection plan should include the following elements, based on the specific conditions of the workplace: 1. Selection of the method for using respiratory protectors ； 2. Conduct medical evaluations for employees who must wear respiratory protection ； 3. Procedure for testing the fit of respiratory protectors ； 4. Correct procedures for using respiratory protection devices in daily routine use and in foreseeable emergency situations ； 5. Procedures and schedules for cleaning, disinfecting, storing, inspecting, repairing, discarding, and maintaining respiratory protectors ； 6. Procedures to ensure sufficient gas quality, volume, and flow rate for the air supply of supplied-air respirators ； 7. Provide employees with training on the knowledge necessary to prevent potential respiratory hazards during routine operations or in emergency situations ； 8. Train employees on the proper use of respiratory protection devices, including how to put them on and take them off, as well as the limitations associated with their use and methods for maintaining them ； 9. Procedures for regularly evaluating the effectiveness of the respiratory protection program. 2.2 Selection of respiratory protection The employer shall evaluate the respiratory hazards present in the workplace, determine the form in which pollutants exist, and assess the workers’ exposure levels. If the employer is unable to determine or reasonably assess the workers’ exposure levels, such an environment shall be considered an Environment Immediately Threatening Life and Health (IDLH). Based on the identified and assessed respiratory hazards, and taking into account the workers’ job requirements, employers must select and provide appropriate respiratory protection for the workers. The selected respiratory protection must be certified by NIOSH, and its actual conditions of use must correspond to those specified in the certification. 2.2.1 Selection of Respiratory Protection for IDLH 1. In IDLH environments, employers must select the following respiratory protection: · NIOSH-approved self-contained breathing apparatus (SCBA) with a usage time of at least 30 minutes ； · Supply-air full-face respirator used in combination with self-contained air reserve respirator ； 2. NIOSH-approved IDLH-specific escape breathing protection ； 3. All oxygen-deficient environments are considered IDLH, but exceptions exist if the employer can prove that, under all foreseeable circumstances, the oxygen concentration in the air can be maintained within the range specified in Table 1; in such cases, the employer may use supplied-air respirators. Table 1 Elevation (feet) Oxygen-deficient environments in which employers may use supplied-air respirators (% oxygen) Below 3000: 16.0–19.5; 3000–4000: 16.4–19.5; 4000–5000: 17.1–19.5; 5000–6000: 17.8–19.5; 6000–7000: 18.5–19.5; 7000–8000: 19.3–19.5. Note: The above exceptions do not apply to elevations above 8000 feet; in environments above 14,000 feet, oxygen-enriched breathing air must be used. 2.2.2 Selection of respiratory protection devices for use in conditions other than IDLH 1. The respiratory protection devices chosen by the employer must be able to protect workers’ health in both normal and emergency situations, in compliance with all OSHA regulations and standards ； · Specified protection factor (to be announced later] ； · Maximum use concentration (to be announced later]. 2. The selected respiratory protective device must be suitable for the chemical properties and physical form of the pollutants ； 3. For protection against toxic gases and vapors, employers must choose: · Air-supplied respiratory protection ； · Air-filtered respiratory protective devices that meet the following conditions: (1) Equipped with a NIOSH-certified service life indicator (ESLI) ； (2) If there is no ESLD suitable for those operating conditions, the employer must establish and implement a schedule for replacing the gas cartridges; this schedule must be based on objective criteria to ensure that the gas cartridges are replaced before the end of their useful life. These objective criteria must be reflected in the respiratory protection plan. 4. For respiratory protection against airborne particulate matter, employers must choose: · Supply-air respirators; · Respirators that use HEPA filters certified by NIOSH under standard 30CFR11, or dust filters certified by NIOSH under standard 42CFR84 ； · For air pollutants with a mass aerodynamic median diameter (MMAD) of at least 2 micrometers in quality aerodynamics, use a filtering respiratory protection device with any NIOSH-approved dust filter. 2.3 Medical evaluation of persons wearing respiratory protection Equipment owners must conduct a medical evaluation (not a physical examination) of those who need to wear respiratory protection, in order to assess their ability to use it. This evaluation must be carried out by a surgeon or another physician with a license in occupational health, and it must be completed before the person starts wearing respiratory protection and before any suitability tests are conducted. This evaluation can be carried out from two perspectives: either by using the medical questionnaire in Appendix C of the standards, or by conducting a medical examination of the wearer, in order to obtain the same information. Further examination of the wearer is then carried out based on this information. Except in the following situations, medical evaluations are not required on an annual basis: 1. When the wearer shows signs or symptoms that affect their ability to wear a respiratory protection device; 2. When it is deemed necessary by the expert conducting the medical evaluation, the wearer’s supervisor, the person in charge of the respiratory protection program, or the personnel performing the fit test; 3. When changes in the working conditions at the workplace (such as temperature, intensity of physical labor, protective clothing) may increase the physical strain on the wearer. An annual medical evaluation is required only when medical assessment experts deem it necessary for the wearer, or when it is explicitly stipulated in the respiratory protection plan. 2.4 Respirator Fit Testing OSHA requires that a fit test be conducted on the wearer before using any negative or positive pressure sealing respirator mask; this is a mandatory requirement. Suitability testing includes qualitative testing (QLFT) and quantitative testing (QNFT), and the testing must be conducted using masks of the same brand, type, and model as those used in actual work. OSHA provides detailed instructions in the new regulations on the specific methods for suitability testing. The purpose of the fit test is to ensure that the respiratory protection device is suitable for the wearer and the working environment in which it will be used. Suitability tests must be conducted when a respiratory protective device is used for the first time and when switching to a different one (type, model, size, manufacturer), as well as once a year thereafter. For respirators that use ambient air for ventilation or powered air-purifying respirators, quantitative or qualitative suitability tests must also be conducted; regardless of whether they operate in negative pressure or positive pressure mode in practical use, the system must be switched to negative pressure mode during the testing. 2.5 Use of Respiratory Protection Equipment: Employers must establish and implement procedures for the proper use of respiratory protection equipment. These procedures include preventing situations that could lead to poor fit of the respirator on the face, ensuring that employees do not stop wearing their respiratory protection in hazardous environments, guaranteeing its continuous proper operation throughout the work shift, and establishing procedures for using respiratory protection equipment in situations of IDLH conditions and indoor building fires. 2.5.1 Face fit of respiratory protectors 1. Regarding the use of a tightly fitting breathing mask, employers must prevent the following from occurring: · Facial hair on the employee’s face preventing proper fit of the respiratory protector to the face or interfering with the function of the valve ； · Any other condition that prevents the respiratory protector from fitting tightly against the face. 2. If the employee wears glasses, goggles, or other personal protective equipment, the employer must ensure that the face seal of the respiratory protection is not affected in any way. 3. For the use of all airtight breathing masks, employers must ensure that employees perform a face fit check every time they put them on; this is a mandatory requirement. Standard Appendix B-1 provides the specific procedures; employees may also use the methods recommended by the respirator manufacturers, but the employer must ensure that these methods meet the requirements of Standard Appendix B-1. 2.5.2 Ensuring the continuous effectiveness of respiratory protection Equipment owners must ensure that, when employees need to clean their respirators, it is done in order to prevent eye or skin irritation caused by the use of those respirators ； When employees feel that toxic gases or vapors have penetrated the gas filter and notice an increase in breathing resistance through the mask ； Or when the filter canister (box) of the breathing mask’s filter needs to be replaced ； Employees must leave the polluted area. When a respiratory protective device starts to leak, gets damaged, or experiences increased resistance, the employer must replace or repair it before the employee returns to the contaminated area. 2.6 Maintenance of Respiratory Protection Devices Employers must provide the necessary conditions to ensure that respiratory protection devices are cleaned and properly disinfected, offer a clean and contamination-free environment for their storage and placement, and inspect all respirators in use to ensure they are functioning properly; any damaged devices must be repaired or discarded promptly. 2.7 Training: Employers must provide employees who use respiratory protection with information and knowledge on all aspects of its use. This training must take place before the use of respiratory protection, be comprehensive and easy to understand, and be conducted at least once a year; it can also be carried out more frequently if possible. Employees who voluntarily use respiratory protection must also be provided with the necessary information. The training content includes: 1. The necessity of using respiratory protection devices, and why only those that are suitable for the user and are used and maintained properly can truly provide respiratory protection ； 2. Usage limitations and protective capabilities of respiratory protectors ； 3. The proper and effective use of respiratory protection in emergency situations, including when the respiratory protection device malfunctions ； 4. Methods for inspecting, donning, doffing, using respiratory protectors, and checking facial fit ； 5. Methods for maintaining and storing respiratory protectors ； 6. How to identify medical signs or symptoms that may limit or impair the effectiveness of respiratory protective equipment. 3. The new standard 42CFR 84 changes the classification of filter media. NIOSH has established new testing and certification standards for dust masks and dust filters, namely 42CFR84, which introduces significant changes to the previous classification of particulate matter filters. These changes are based on the finding that the presence of oily substances reduces the filtering efficiency of the filters; therefore, the filters are divided into 3 categories: · Category N – not suitable for oily environments ； · Class R – Oil-resistant environment, but with a time limit ； · Class P – Oil-resistant environment. Previous research indicates that the mass aerodynamic median diameter (MMAD) of the aerosols generated by mechanical crushing is greater than 2 micrometers. NIOSH uses a particle size range for testing particulate filters as follows: · For NaCl aerosols, the calculated median diameter is 0.075 + 0.020 micrometers, with a standard error not exceeding 1.86 ； · DOP aerosols: the calculated median diameter is 0.185 + 0.020 micrometers, with a standard error of no more than 1.60. The flow rate required is 85+4 liters per minute for a single filter, and 42.5+2 liters per minute for two filters; this meets the breathing volume needs of workers engaged in heavy physical labor. Based on the filtration efficiency test results, the filter media are classified into 3 grades, namely 95%, 99%, and 99.97% (see Table 2). Filter media with a filtration efficiency of 99.97% are considered high-efficiency filter media (HEPA). Table 2 42 CFR 84 Aerosol Testing – Minimum Dust Retention Efficiency: NaCl, non-oily aerosols; DOP, oily aerosols*. DOP, oily aerosols** 95% N95 R95 P95 99% N99 R99 P99 99.97% N100 R100 P100 * When oil-based substances are present, there are time limits on the use of these materials; DOP: dioctyl ester ； ** Use the time limit provided by the manufacturer. 4. Specified Protection Factor: The concept of the specified protection factor (APF) refers to the level of protection that a particular respiratory protective device can provide against air pollutants in the workplace. The higher the protection factor, the higher the concentrations of pollutants for which it is suitable. Currently, OHSA does not specify protective factors uniformly in 29CFR1910.134. However, in the selection of respiratory protection devices, the protective factors specified by the ANSI Z88.2 Respiratory Protection Practice Committee–1992 are generally used in practice. (ANSI: American National Standards Institute.) (1) Air-filtered: Half-mask – 10; Full mask – 50; (2) Powered-air-purifying respirators: Half-mask – 50; Full mask – 1000; (3) Air-supplied respirators: Half-mask – 50; Full mask – 1000; (4) Self-contained breathing apparatus – 1000. In practical applications, these specified protective factors help users choose respiratory protection devices with appropriate levels of protection based on the degree to which pollutant concentrations in the workplace exceed safe levels. 5. The gaps we face and the work that needs to be done: Our country has various gaps in terms of respiratory protection compared to industrially developed countries, and it is unrealistic to eliminate these gaps in a short period of time. What we need to do is to gradually reduce these gaps and move closer to international standards, rather than staying in the same place. Specifically, the main gaps between our country and the United States lie in the following areas: Standards – China, United States. Health standards: These standards rely on short-term sampling, with on-site tests measuring instantaneous concentrations; as a result, the test results are quite variable ； U.S. health standards use the 8-hour time-weighted average concentration measured on-site as the representative average concentration ； Testing standards for respiratory protectors – Dust filters; the impact of oily environments on the filtration efficiency of particulate filters is not taken into account ； Particle filter media are classified into N, R, and P categories based on their oil resistance ； Testing standards for respiratory protection devices – Dust-filtering media: The testing of the filtration efficiency of particulate-filtering media involves using particles with a size of less than 5 microns, where 90% of these particles are within that size range. The required filtration efficiency is 395% for complex types of filters and 390% for simpler types. Testing is carried out using particles of a single size that can most easily penetrate the filter media, with filtration efficiencies classified into three levels: 95%, 99%, and 99.97% ； Testing standards for respiratory protectors – Service life indicators. There is a lack of objective means to determine the service life of filters for toxic gases and vapors, such as indicators that show when the service life has ended or a schedule for replacement ； There must be a service life indicator or a schedule for replacing the filter cartridge; some manufacturers provide software that allows the service life to be determined based on the operating environment and conditions of use ； Testing standards for respiratory protection devices – Testing flow rate: The required flow rate for testing respiratory protection devices is 30 liters per minute, which is not sufficient to meet the needs of workers engaged in physical labor ； The test flow rate for respiratory protectors is 85–95 liters per minute, which meets the breathing volume requirements for workers engaged in heavy physical labor ； There are still no standards for selecting respiratory protectors ； There are specific criteria for selecting respiratory protection devices ； Selection of respiratory protectors – specified protection factor; the concept of protection factor is not introduced ； The concept of a specified protection factor has been introduced; although it is not formally defined in OSHA standards, it is widely adopted in practice, allowing users to choose respiratory protection devices with different protection factors based on a comparison between the pollutant concentration and the relevant standards ； Management – Respiratory Protection Program: There are no requirements for companies to establish a respiratory protection program ； If there are occupational respiratory hazards, the employer must establish a written respiratory protection plan ； The use of the – suitability test: Regulations do not require a suitability test for respiratory protectors ； Regulations require mandatory suitability tests, including quantitative and specified qualitative tests, to be carried out once a year ； Use – Face seal check; no requirement for face seal check each time it is worn ； Regulations require that users perform a face fit check every time they wear it ； Training: Not enough attention is paid to training, and available resources are limited ； Great emphasis is placed on training, which is an essential part of the respiratory protection program ； Voluntary use: There is no approval for those who voluntarily request to wear respiratory protection when the concentration is within limits. Even if the concentration is within limits, employees can still voluntarily request to wear it. It should be noted that China’s current standards for respiratory protection equipment have been revised several times, resulting in improvements. However, it is also evident that there is a significant gap between China and industrially developed countries such as the United States in terms of testing methods and instrumentation; moreover, much work remains to be done to improve regulatory frameworks and standard systems. It is reported that the **Economic and Trade Commission is currently working on formulating standards for the selection of respiratory protectors. This will undoubtedly serve as an important supplementary standard to the existing respiratory protection standards. It will help companies determine which respiratory protective devices are suitable and effective, providing a basis for occupational health inspections. Furthermore, it will contribute to the proper protection of workers’ health, enhance the efficiency of companies’ investments in worker health protection, and support the improvement of domestic production techniques for respiratory protective devices. References: Edited by Liu Tie**, published by China Social Sciences Press, p. 6. ISBN 7-80146-409-5, 2000. She Qiyuan, Introduction to the New U.S. Standards for Respiratory Protection Equipment – 42 CFR 84, Chinese Labor Protection Equipment, P. 43, Vol. 1, 2000. For specific questions or recommendations regarding PPE products, please contact the technical staff at Shanghai Hangli Company. Thank you. Contact person: Zhao Jiabin Phone number: 64280398*213