Protection standard of Stomatological hospital during novel coronavirus infection epidemic stage 5: Selection criteria for protective clothing

ZHANG Yi, HE Fangli, Hou Rui, FAN Haibing, LIU Yan, LIU Wen, ZHANG Yanxia, CHEN Jing, LV Nini, LIU Rui, KONG Liang, ZHANG Ming

(710032 Xi’an, State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral diseases & Shaanxi International Joint Research Center for Oral Diseases, School of Stomatology, The Fourth Military University, China)

 

[Abstract] Oral health care workers are at increased risk during outbreaks of novel coronavirus. Protective clothing is an important protective material for medical staff as an important role in infection control. This paper mainly introduces the origin, classification, evaluation indexes, standard requirements and usage scenarios of modern medical protective clothing, so as to provide a reference for the correct selection for dental staff.

[Key words] Novel coronavirus; Infection control; Protective clothing; Evaluation standard

The main transmission routes of COVID-19 are droplet transmission and contact transmission. In the oral diagnosis and treatment, the medical staff need to wear protective clothing to protect themselves from droplets and aerosols, in order to protect their safety. During the covid-19 epidemic period, as the supply of protective clothing meeting the national standards was in short supply, the national document made it clear that the use of foreign standard protective clothing could alleviate the current shortage of supplementary protective clothing.

1. The emergence of modern medical protective clothing and its role in infection control

More than a century ago, to protect patients from bacterial infections on their skin and clothing during surgery, medical personnel wore specially designed surgical clothing to isolate and reduce the risk of infection.

In 1886, Bergman designed a surgical gown in the form of a white coat, which became the precursor to modern surgical gowns. In 1918, during the Spanish flu, when doctors entered the epidemic area, they began to use white protective clothing to protect themselves. During the Second World War, the US military developed a water-repellent fabric made of cotton and mercerized cotton. In the 1990s, with the continuous emergence of infectious diseases, medical personnel usually wear isolation protective clothing to protect patients during the diagnosis and treatment of infectious diseases. With the development of material technology, fabrics that can block liquids, particles, microorganisms, etc. are gradually used in the production of protective clothing. Conventional protective clothing has gradually developed into special protective clothing. Protective clothing in various countries has made great progress in the past 30 years.

After the outbreak of SARS in 2003, China promulgated the "Technical Requirements for Medical Disposable Protective Clothing" GB19082-2003, and began to propose uniform standards for Chinese medical protective clothing. Local governments have also issued the "General Technical Conditions for Disposable Protective Clothing" DB42 / 245-2003, "Disposable protective isolation clothing" (Beijing) and other standards. Since then, with the continuous development of standards and concepts for surgical gowns, isolation suits, and protective clothing, China and the pharmaceutical industry have successively issued "Technical Requirements for Medical Disposable Protective Clothing" GB19082-2009 and "Technical Specification for Hospital Isolation" WS / T311-2009 "Surgery sheets, surgical gowns and clean clothes for patients, medical personnel, and equipment" YY / T0506-2016, "Guidelines for the selection and evaluation of medical protective clothing" YY / T1498-2016, "Liquid barrier properties and classification of medical protective clothing "YY / T1499-2016," Technical Specifications for Single Classification and Performance of Medical Protective Clothing and Isolation "T / CTES1013-2019 and other standards. The formulation of these standards clarifies the standards for the manufacture and use of surgical gowns, isolation gowns, and medical protective clothing. The application scenarios and functions of surgical gowns, isolation clothing, and medical protective clothing commonly used in clinical practice are shown in Table 1:

Table 1 Application scene of operation clothing, isolation clothing, medical protective clothing

Name of goods	Application	Application scenarios
Surgical gown	Prevent health care workers from passing bacteria from skin and clothing to patients	Dressing in operating room
Isolation gown	Barrier liquid contamination	Medical institutions outpatient, ward, laboratory and other common isolation
Medical protective clothing	Isolate microorganisms and prevent liquid contamination	For emergency relief or medical personnel entering the quarantine area for infectious diseases

According to the "Single Rating and Performance Technical Specifications for Medical Protective Clothing and Isolation", protective clothing is divided into 4 levels according to the protection level, and the requirements for water resistance and anti-synthetic blood are different at different levels, of which level 1 Lowest, 4th highest. According to "Surgery Sheets, Surgical Gowns, and Clean Clothes for Patients, Medical Staff, and Instruments," surgical gowns and gowns do not have clear protection classification requirements, but surgical gowns have index requirements in terms of water resistance and resistance to microbial penetration. There is no clear requirement for the isolation gown, and the protection level of the isolation gown is slightly lower than that of the surgical gown; and the protection level of the medical protective clothing should reach at least a protection level of 2 or higher. At the same time, according to the China National Drug Administration's classification catalog, surgical gowns and medical protective clothing belong to the second-class medical device management category, while isolation clothing can be a first-class medical device management category.

2. Foreign evaluation standards for protective clothing

According to the notice of the China National Drug Administration during the epidemic, medical devices that meet the relevant standards of the United States, the European Union and Japan can be used for emergency purposes. Subsequently, the National Health and Health Commission also issued the "Notice on Strengthening the Management of Medical Protective Articles During an Epidemic", which clearly restricted some EU standard protective clothing for emergency use. In the EU EN series standard protective clothing, it can be divided into two categories: biological and chemical, as shown in Table 2.

Table 2 European standards for protective clothing

Standard name	Standard content
EN 14126 Medical biological protective clothing standards	It mainly focuses on the anti-penetration resistance of protective clothing of blood, body fluid, solid particles and other microbial particles
EN 943 Standard for protective clothing for liquid and gaseous chemicals(EN Type1、EN Type 2)	It mainly focuses on the anti-penetrability of protective clothing of liquid smoke and solid particles
EN 14605 Liquid chemical protective clothing standard(EN Type 3、EN Type 4)	It mainly focuses on the anti-penetrability of protective clothing of liquid or fog particles
ISO 13982 Standard for protective clothing for solid particles(EN Type 5)	It mainly focuses on the anti-penetration of solid particles and aerosols
EN 13034 Personal chemical protective clothing(EN Type 6)	It mainly focuses on the anti-penetration of protective clothing of chemical liquids

It is clearly stated in the notification document of the Chinese National Health Construction Commission that protective clothing for medical supplies that can be used urgently during the new type of coronavirus pneumonia should meet the EN14126 standard (where the liquid barrier level is above level 2) and obtain EU CE certification, or EN14605 Type3 and Type4 standards, Or EN1SO13982-1 & 2 standards.

Chinese medical protective clothing must meet the requirements of GB19082-2009 medical protective clothing technical standards. The standards include structure, specifications, liquid barrier ability, breaking strength, breaking elongation, filtration efficiency, flame retardant performance, antistatic property, and static attenuation, Skin irritation, microbial indicators, ethylene oxide residues and other 13 indicators were required. Among them, the indicators that reflect the protective performance of the protective clothing liquid barrier include: water resistance, moisture permeability, resistance to synthetic blood penetration, surface moisture resistance. Compared with European and international standards, Chinese standards do not require biological penetration of protective clothing, but regulate it through resistance to synthetic blood penetration and filtration efficiency (particulate matter). In accordance with the protective clothing standards in the requirements of the new coronavirus pneumonia epidemic protection level, based on the protective indicators of medical protective clothing in China, the EU protective clothing standards can be compared for emergency use. The comparison of the core evaluation indicators is shown in Table 3.

Table 3 key parameters comparison for protective clothing

Standard	Impermeability to water (hydrostatic pressure)	Moisture transmission	Resistance to synthetic blood penetration	Surface moisture resistance	Particulate filtration efficiency	Anti-liquid permeability
“Technical requirements for disposable protective clothing for medical use”GB19082-2009	Yes	Yes	Yes	Yes	Yes	No
EN14126(Liquid barrier grade>2)	Yes	No	Yes	No	Yes	Yes
Type 3 Liquid dense protective clothing(EN14605)	No	No	No	No	No	Yes
Type 4 Spray tight protective clothing(EN14605)	No	No	No	No	No	Yes
Type 5 Anti-solid particles protective clothing(ISO 13982-1&2)	No	No	No	No	Yes	No

3. Choice of protective clothing during the COVID-19

During the outbreak of new coronavirus pneumonia, according to the Chinese government requirements for protective clothing and related policies and regulations, three levels of epidemic protection are set, and the protective clothing that needs to be used should meet the corresponding standards. Due to the lack of medical protective clothing during the epidemic period, it complies with China's GB19082-2009 standard. Sterilized medical devices with a medical device registration certificate can be used as third-level protective clothing; in line with China's GB19082-2009 standard

However, those without sterilization and with a medical device registration certificate can be used as secondary protective clothing; anti-virus protective clothing that complies with EN14126, and those with a liquid barrier rating greater than 2 can be used as secondary protective standard protective clothing. European EN standard Type 3 liquid dense protective clothing, Type 4 spray dense protective clothing and Type 5 anti-solid particulate protective clothing can be used as secondary protection standard protective clothing; other protective clothing can be used as primary protection. Specific protection standards and usage scenarios are shown in Table 4.

Table 4 Application scene of medical protective clothing

Product rating	Name	Standards should be comply with	Application scenarios
Level 3 protection	Medical disposable protective clothing (sterile)	GB 19082-2009	1. Isolated intensive care ward room and other places with strict control of microbial indicators; 2. Laboratory or CDC nucleic acid tester; 3. Health care people who perform sputum aspiration, airway sampling, endotracheal intubation and other operations for patients. 4. People who touch confirmed cases’ body fluids, blood, secretions, excreta, etc
Level 2 protection	1. Disposable protective clothing for medical use(Non-sterile); 2. Protective clothing in compliance with EU EN14126 and CE certification; 3. Liquid dense protective clothing (type 3); 4. Spray tight protective clothing (type 4); 5. Anti-solid particles protective clothing(type 5 can’t be used for  disinfection of epidemic focus and wet operation)	1. GB19082-2009(Non-sterile); 2. EN14126; 3. EN14605; 4. ISO13982-1&2	1. Isolation observation ward (room); 2. Isolation ward (room); 3. People who close contact of confirmed or high-risk, suspected cases (including personnel on transfer); 4. Virus sample collector; 5. Transfer of confirmed or suspected cases; 6. Terminal sterilizer; 7. Cadaver handler
Level 1 protection	Other protective clothing	Reached the provisions of gb19082-2009 on breaking strength, elongation at break and filtration efficiency.	1. Fever clinic; 2. Laboratory sample handover personnel; 3. Cadaver transporter

According to the actual diagnosis and treatment during the epidemic in China and the personal protective equipment of medical staff, the protection level can also be divided into three levels during oral diagnosis and treatment:

when performing maxillofacial surgery for diagnosed and suspected patients, it is recommended that medical staff perform China level III protection requirements, wearing medical disposable medical protective clothing (sterile) to ensure the safety of medical staff during the operation.

In the oral spatter diagnosis and treatment area, due to the presence of pollutants such as droplets and aerosols, it is recommended that medical personnel implement national secondary protection requirements and wear protective clothing corresponding to secondary protection. At the same time, disposable surgical gowns or gowns can be worn outside protective clothing Save the use of protective clothing and avoid cross infection by changing disposable surgical gowns or gowns for each patient.

For the general diagnosis and treatment area of the oral cavity, medical personnel can wear protective equipment such as disposable isolation gown, disposable surgical gown, etc. as required. Specific wearing requirements are shown in Table 5.

Table 5 Suggestion of medical protective clothing in diagnosis and treatment of oral diseases

Application scenarios	Protection scenario	Protective clothing requirements	Dressing precautions
Operating room of oral and maxillofacial surgery (operation for confirmed and suspected patients)	Level 3 protection	Medical disposable protective clothing (sterile)	1. Strictly follow the requirements for aseptic operation in the operating room before the operation, wear protective clothing according to the procedures and specifications for wearing protective clothing in the sterile area, and perform mutual inspection; 2. Protective clothing should be closely fitted with goggles and masks, and no protective gaps shall be allowed; 3. If the protective clothing is damaged during the operation, it should be replaced or shielded immediately; 4. After the operation, remove the protective clothing in strict accordance with the procedure specification, and conduct sealing and isolation treatment in accordance with the procedures of pollutants and medical waste treatment.
Oral splash diagnosis and treatment area	Level 2 protection	1. Disposable protective clothing for medical use(Non-sterile); 2. Protective clothing in compliance with EU EN14126 and CE certification; 3. Liquid dense protective clothing (type 3); 4. Spray tight protective clothing (type 4); 5. Anti-solid particles protective clothing(type 5 can’t be used for  disinfection of epidemic focus and wet operation)	1. In the clean area outside the splash treatment area, wear the protective clothing according to the operating procedures and specifications, and conduct mutual inspection; 2. The protective clothing should be closely fitted with the goggles and masks, and no protective gap is allowed; 3. Wearing disposable isolation clothing or surgical clothing, replace each patient. In case of damage, immediately replace the goods for shielding protection; 4. Do not leave the splash area before the end of the shift; 5. When the treatment is over or you must leave the splash clinic, the protective clothing should be removed in accordance with the procedures and specifications in the splash clinic and sealed and treated in accordance with the direct waste disposal procedure.
General oral area(As well as hepatitis b, HIV and other diagnosed common patients)	Level 1 protection	1. Disposable isolation gown; 2. Disposable operating gown	1. Dress according to dress code and check each other before treatment; 2. During the treatment if there is obvious permeability or large area of pollution, the cloth should be replaced; 3. After the treatment should be in accordance with the procedures to remove disposable isolation clothing or operating clothing, and according to the medical waste treatment procedures for sealing isolation treatment

During the epidemic period, oral clinics should be limited, and confirmed or suspected patients should not be treated in principle. Diagnosis and treatment of COVID-19 pneumonia should be performed by designated hospitals before oral disease diagnosis and treatment. Maxillofacial surgery for ordinary patients is also recommended to be suspended and should not be implemented until the epidemic is over. If it is really necessary to carry out diagnosis and surgery, the diagnosis or treatment of oral spatters of confirmed or suspected patients should be in accordance with the three-level protection standard, and the ordinary patients' maxillofacial surgery should be wearing appropriate protective clothing according to the first-level protection standard.

4. Conclusion

Due to the special nature of oral diagnosis and treatment, vigilance of droplets and aerosols to medical personnel should be alert. Medical staff who perform clinical diagnosis and treatment during the epidemic situation must strictly implement the requirements of protection standards and correctly choose whole-body protective clothing. At the same time, all hospitals and clinics should rationally allocate and use protective clothing resources in accordance with the development of the epidemic situation to achieve proper protection while avoiding waste of resources caused by excessive protection, and they should also be alert to the risk of infection caused by inadequate protection of medical staff.

https://www.pioon.com