1.2.1 The Importance and Role of Compiling the Standard and the Code

With the development of medical science in China, the improvement of medical technology, and the changes in the public's demand for medical care, hospitals are faced with increasingly heavy tasks of new construction and expansion; surgical techniques in the various medical departments have become ever more advanced, difficult, and complex, and the requirements for the cleanliness and functionality of operating rooms have become ever higher. According to statistics, by 1998 there were 16468 hospitals nationwide, of which 15270 were hospitals at or above the county level, 7498 were hospitals with more than 100 beds, and 788 were hospitals with more than 500 beds. At that time, about a hundred hospitals had been converted into clean operating departments (rooms), accounting for 0.75% of the total. Consequently, some medical institutions competed to renovate their operating rooms; by the time of the "International Symposium on Hospital Architectural Design and Equipment" held in Beijing in 1998, attention to the construction of hospital operating departments had become a hot topic, it being held that the hospital operating department is the key link in hospital infection control and one of the markers of a hospital's technical level. Since then, nearly a thousand clean operating rooms have been put into construction every year. However, China had never had unified standards and codes for the construction of clean operating departments. Although the Architectural Technical Code for Clean Operating Departments of Military Hospitals promulgated in 1995 played a milestone role in promoting progress, it had, after all, no obvious binding force on the vast majority of local hospitals; in addition, a number of foreign-related engineering companies, acting under the banner of their respective national standards, created a situation in which multiple national standards ran in parallel. Owing to the lack of applicable guiding standards and correct measures for guidance, the existing problems were mainly manifested in the following four aspects: ① the institutions undertaking the construction and renovation of clean operating rooms had no qualification certification, and a considerable proportion of them did not possess professional technical strength or design and construction capabilities, to say nothing of being familiar with the characteristics of clean operating departments; ② manufacturers rushed headlong into the field, and the quality of clean operating room equipment was not guaranteed, so that many products sold on the market were of inferior quality; ③ project contracting and subcontracting did not go through normal procedures, the market for the construction and renovation of clean operating rooms was in disorderly competition and in a seriously uncontrolled state, and funds were greatly wasted—built according to so-called foreign standards, a single operating room cost an extra 300,000 to 400,000 yuan or so; ④ completed operating room projects did not undergo completion acceptance inspection and comprehensive evaluation, and there was no department to check the overall quality of the projects. In short, on the one hand, project quality was declining; on the other hand, the tendency to chase after the new and the high-end showed a continuously expanding trend. Therefore, the Department of Planning and Finance of the Ministry of Health, the competent authority for health, decided to place the compilation of unified national construction standards and architectural technical codes for clean operating departments on the agenda for immediate implementation. For the earlier our own standards and codes were compiled, the earlier results would be seen in the construction of hospital operating departments, the development of the domestic operating room industry, the rational use of investment, and so on.

The above constitutes the subjective and objective needs for formulating unified construction standards and architectural technical codes for hospital clean operating departments. The Standard has now been in effect since October 1, 2000, and the Code was promulgated on December 1, 2002. The introduction here is based mainly on the Code.

1.2.2 The Guiding Ideology and Basic Principles for Compiling the Code

The guiding ideology is: as a national standard and code, it should both absorb mature experience and achievements at home and abroad and proceed from China's national conditions, and must on no account depart from reality; it should aim at the popularization and widespread application of clean technology in operating departments—for example, the "quasi-clean operating room" is more universally applicable to small and medium-sized hospitals and county-level hospitals—while at the same time maintaining a certain forward-looking awareness.

The basic principles are:

(1) The clean operating department is a multifunctional, comprehensive whole, an organic combination of hygiene and engineering; this is reflected in aspects such as the scope of application, architectural decoration, and air conditioning and purification, as well as in specific measures such as airborne bacteria, settling bacteria, and dynamic and static states. Therefore, the standards and codes for clean operating rooms do not conflict with the hospital disinfection and hygiene standards; rather, they should be an important supplement to and deve development.

(2) Highlighting the characteristics of the operating room as a biological cleanroom, that is, taking the control of viable particles as the goal, emphasizing that reducing postoperative infection should be a whole-process control, and that comprehensive measures must be taken to reduce the risk of cross-infection. The purpose of the Code should be to establish the basic principles of a safeguard system, so as to achieve the goal of both preventing bacteria and dust from contaminating the operating rooms and preventing pollution of the external environment.

(3) Breaking away from the concepts and practices of industrial cleanroom technology, and highlighting the protection of the key area, namely the operating zone. This is more practical and economical.

1.2.3 Main Contents and Features of the Code

The Code consists of a foreword, ten chapters of main text, and one appendix; together with the compilation notes, it contains 66 000 characters.

(1) Regarding the scope of application. Only the following points are emphasized here: ① The Code applies not only to a complete clean operating department, but also to one or several clean operating rooms and their auxiliary rooms built within a non-clean operating department (or built in a scattered manner, or of an experimental nature); ② ordinary operating departments using ventilation and air conditioning are, on the whole, not covered by the Code. Since ordinary ventilation brings in dust and bacteria, and ordinary air conditioning is a breeding ground for bacteria, such departments must also at least comply with the Code's provisions on supply air filtration and carry out the necessary air purification treatment. If this provision were not made—given that air conditioning is the bare-minimum equipment in any operating room—it would inevitably leave behind the hidden danger of large-scale cross-infection, so that adopting air conditioning would not raise the grade of the operating room but would instead increase the opportunities for bacterial contamination. With the Code making such a provision, as evaluated in the minutes of the national review meeting, it has "pointed out the direction for the construction of clean operating departments to avoid detours."

(2) Regarding the composition of the clean operating department. Adopting the concept of the clean operating department rather than that of the clean operating room is based on the understanding that the control of infection must be whole-process and all-round.

In the chapter on terminology, the Code gives a specific definition of the clean operating department: it is "a self-contained functional area composed of clean operating rooms, clean auxiliary rooms, and non-clean auxiliary rooms." If an operating room has no auxiliary rooms, its function can hardly be brought into full play. The Code stipulates that clean auxiliary rooms may be located within the clean area, while non-clean auxiliary rooms shall be located in the non-clean area.

To make it easier for designers to implement the Code, the applicable operations and content hints are given for operating rooms and auxiliary rooms of each grade, as shown in Table 1 and Table 2.

Table 1 Classification of clean operating rooms

Grade Name of operating room Class of surgical incision Hints on applicable operations
Ⅰ Special clean operating room Ⅰ Joint replacement operations, organ transplant operations, and aseptic operations in neurosurgery, cardiac surgery, ophthalmology, etc.
Ⅱ Standard clean operating room Ⅱ Class I incision aseptic operations in thoracic surgery, plastic surgery, urology, hepatobiliary-pancreatic surgery, orthopedic surgery, and general surgery
Ⅲ General clean operating room Ⅲ Operations in general surgery (excluding Class I incision operations), obstetrics and gynecology, etc.
Ⅳ Quasi-clean operating room Ⅳ Anorectal surgery and contaminated operations, etc.

Table 2　Classification of Main Clean Auxiliary Rooms

Grade Room name
Ⅰ Special laboratory requiring aseptic operations
Ⅱ Extracorporeal circulation perfusion preparation room
Ⅲ Scrub room
Disinfection preparation room
Pre-anesthesia room
Storage room for disposable items, sterile dressings and instruments, and precision instruments
Nurses' station
Clean corridor
Intensive care unit (ICU)
Ⅳ Recovery (anesthesia recovery) room and changing room (second change)
Cleaning corridor

Once the necessary components of the clean operating department have been clarified, there is a basis for considering its scale, and it will not end up with a reputation for being "incomplete" after construction.

An important part of the composition is the standard for operating room area, which is clearly specified in the Standard. It opposes blindly pursuing large sizes while also taking into account the needs of modern operating rooms, provides reasonable areas, and allows an expansion of 25% under certain conditions, which can be said to be quite practical and flexible.

(3) On the classification of rooms in the clean operating department. According to the aforementioned guiding ideology and principles, the various types of clean rooms in the clean operating department belong to biological clean rooms, with the control of viable particles as the main objective. Therefore, classification should be based on bacterial concentration, while emphasizing that air cleanliness is a necessary safeguard condition. This not only conforms to the habits of medical staff and facilitates understanding and the adoption of comprehensive measures for all-round control during implementation, so as to avoid regarding air purification as omnipotent; at the same time, it also shows that a clean operating room is different from an ordinary operating room that has merely been disinfected—without air purification measures, it cannot be regarded as a clean room, thereby also pointing out the essence of the clean operating department.

The classification of rooms in the clean operating department is shown in Tables 3 and 4.

Table 3　Classification Standards for Clean Operating Rooms

Grade Operating room name Maximum average bacterial concentration by settling method (floating method) Operating area Maximum average bacterial concentration by settling method (floating method) Surrounding area Maximum surface bacterial contamination density/(cfu/cm²) Air cleanliness class Operating area Air cleanliness class Surrounding area
Ⅰ Special clean operating room 0.2 cfu/[30min·φ90 dish (5 cfu/m³)] 0.4 cfu/[30min·φ90 dish (10 cfu/m³)] 5 Class 100 Class 1000
Ⅱ Standard clean operating room 0.75 cfu/[30min·φ90 dish (25 cfu/m³)] 1.5 cfu/[30min·φ90 dish (50 cfu/m³)] 5 Class 1000 Class 10 000
Ⅲ General clean operating room 2 cfu/[30min·φ90 dish (75 cfu/m³)] 4 cfu/[30min·φ90 dish (150 cfu/m³)] 5 Class 10 000 Class 100 000
Ⅳ Quasi-clean operating room 5 cfu/[30min·φ90 dish (175 cfu/m³)] 5 Class 300 000

Note: 1) For the floating method, the maximum average bacterial concentration adopts the value in parentheses. The bacterial concentration is the result obtained by direct measurement, not the result of mutual conversion between the settling method and the floating method.

2) For Class Ⅰ operating rooms dedicated to ophthalmology, the surrounding area shall meet the Class 10 000 requirement. Table 4 Grade standards for clean auxiliary rooms (as-built or at-rest)

Grade Maximum average bacterial concentration by the settling method (airborne method) Maximum surface bacterial contamination density /(count/cm²) Air cleanliness class
Ⅰ Local: 0.2 count/[30min·φ90 dish (5 count/m³)] Other areas 0.4 count/[30min·φ90 dish (10 count/m³)] 5 Local Class 100, other areas Class 1000
Ⅱ 1.5 count/[30min·φ90 dish (50 count/m³)] 5 Class 10 000
Ⅲ 4 count/[30min·φ90 dish (150 count/m³)] 5 Class 100 000
Ⅳ 5 count/[30min·φ90 dish (175 count/m³)] 5 Class 300 000

Note: For the airborne method, the maximum average bacterial concentration adopts the values in parentheses; the bacterial concentration is the directly measured result, not the result of mutual conversion between the settling method and the airborne method.

In the Code, the grades of clean operating rooms are determined according to different types of surgery. The classification of operating rooms is related only to the surgical content, and does not involve the grading of the operating department, nor is it a hospital grading standard. In principle, high-grade clean operating rooms are suitable for operations on vital organs, because once infection occurs, the consequences are serious. In economically developed countries, for example, the Swiss air-conditioning standard divides operating rooms into three grades, the German hospital standard has two grades, the American College of Surgeons divides operations into three grades, Japan divides the entire hospital into five grades (the rooms of the operating department consist of three grades in the front zone, namely the highly clean, clean and quasi-clean zones, and two grades in the rear zone, namely the general zone and the contamination-spread-prevention zone), and the United Kingdom is in fact divided into two grades, namely the ultra-clean air supply system and the conventional air supply system. These divisions are all not very clear, and their applicable contents are vague. Considering that regional differences in our country are still rather large at present, in order to suit various situations in different regions, four different grades of clean operating rooms are established, with the Grade Ⅱ clean operating room as the reference: those with still higher requirements are the Grade Ⅰ special clean operating rooms, and those with slightly lower requirements are the Grade Ⅲ general clean operating rooms. So that ordinary hospitals can all have clean operating rooms and any operation can be performed in a clean operating room, Grade Ⅳ is specially established as the quasi-clean operating room, which is of positive significance for raising the level of operating rooms across the board. The minutes of the national review meeting evaluated this grading as "both scientifically advanced and reasonable; both grounded in the current national conditions and oriented toward future development".

The Code breaks through the industrial-cleanroom framework in the similar British and Japanese standards and absorbs the German idea of protecting the key areas, and, based on our country's own important theory and achievements on the mainstream zone, formulates the grading of operating rooms separately for the operating zone and the surrounding zone. The chapter "Terms" of the Code gives the definitions of the operating zone and the surrounding zone: the operating zone is "the operating table and its surrounding area that require special protection. In a Grade Ⅰ operating room, the operating zone refers to the area after extending at least 0.9 m outward on each of the two sides of the operating table and at least 0.4 m outward at each of the two ends (including the operating table); in a Grade Ⅱ operating room, the operating zone refers to the area after extending at least 0.6 m outward on each of the two sides of the operating table and at least 0.4 m outward at each of the two ends (including the operating table); in a Grade Ⅲ operating room, the operating zone refers to the area after extending at least 0.4 m outward on each of the four sides (including the operating table). Grade Ⅳ operating rooms are not divided into an operating zone and a surrounding zone. In a Grade Ⅰ ophthalmology-dedicated operating room, each side of the operating zone is not less than 1.2 m". The surrounding zone is "the other areas in the clean operating room other than the operating zone", and thus the scheme of protecting the operating zone by means of concentrated air supply is proposed more systematically and concretely than in the German standard. This is not only conducive to contamination control but also convenient for operation. In recent years, the National Construction Engineering Quality Inspection Center has done exactly this in its measurements in hospitals, and it has been well received by users and engineering contractors. Such zoning and grading is the first of its kind internationally. The German standard only gives such a general criterion as that the contamination of the operating zone can be half that of the surrounding zone, but does not carry out zoning and grading on this basis, whereas, after the Code formulates standards separately by zone, quantitative criteria can also be established for concentrated air supply utilizing the mainstream zone principle.

The determination of the bacterial concentrations in the specific grading makes use of domestic achievements on the relationship between airborne bacteria and settling bacteria, while also taking into account the existing foreign data, which makes the grading data of the Code more scientific.

The minutes of the national review meeting pointed out that the Code "provides very operable specific standards and principles" and "reaches the level of similar international standards as a whole in guiding ideology, specific content and technical parameters, and has distinct features and innovations".

(4) On architecture. Architecture is the foundation of the clean operating department and is the first thing to be clarified after the composition and grading have been determined. It is divided here into three parts: the architectural environment, the internal plan layout and the architectural decoration. The entire content centers on the practical principle of serving the function, avoiding one-sided Pursuit of decoration.

In the built environment, particular emphasis is placed on the issue of the most frequent wind direction and the second most frequent wind direction with respect to the environment of the clean operating department within the hospital. This differs from the conventional practice of expressing it only in terms of the prevailing wind direction or the most frequent wind direction; instead, the concept of pollution wind frequency is utilized.

In the floor plan layout, a clear answer is given to one of the difficulties encountered in design, namely the corridor issue, and specific criteria are established for when to use a single corridor, double corridors, or multiple corridors. For the first time, it is explicitly stated that air showers shall not be used in the operating department, as they are impractical for operating rooms and even harmful; for the first time, the Code specifies the design of buffer rooms based on research conclusions (area not less than $3m^2$, cleanliness level the same as the environment being entered, but not higher than Class 1000; when one door is not closed, the other door cannot be opened). In view of the emerging trend of completely rejecting terrazzo and ceramic tiles and using high-grade finishes uniformly regardless of the situation, the Code, based on material properties and practice, explicitly points out that these two materials may be used. The Code stipulates that "the walls of Class I and Class II cleanrooms may use integral or prefabricated wall panels, and the walls of Class III and Class IV cleanrooms may also use large ceramic tiles or coatings."

It is stipulated that clean operating rooms shall have no exterior windows, while Class III and Class IV clean auxiliary rooms may have double-sealed windows. The treatment of junctions between indoor surfaces has gone through reversals in China; for example, in pharmaceutical factory design, it was first required that all junctions be made as rounded corners, but now no mandatory requirements are imposed. This is mainly because the function of such sanitary coves is not understood, and designs blindly follow those of foreign companies in China. The function of sanitary coves lies mainly in the floor cove, which serves to prevent the accumulation of contamination and to facilitate cleaning. Therefore, the Code holds that the correct attitude is to strictly stipulate that the floor sanitary cove must be a rounded corner, while leaving the treatment of other junctions unspecified.

To overcome the widespread habit of performing surgery with the door open and to maintain positive indoor pressure, the Code proposes that automatic doors must have a time-delay setting; to reduce opportunities for contamination and facilitate use, the Code stipulates that scrub rooms should preferably be dispersedly arranged, and so on. All of these measures are intended to fully bring into play the function of the building in serving surgery.

(5) Regarding basic equipment. The basic equipment of an operating room refers to the facilities that need to be architecturally assembled and installed inside the operating room, such as shadowless lamps, instrument cabinets, and gas supply devices. These are related to both the floor plan structure and the airflow design of the operating room, and must also be determined in advance. This part is very necessary and practical content for the design and use of the clean operating department, and is also an aspect of ensuring the standardization and modernization of clean operating rooms; no such specialized content yet exists in relevant foreign standards and codes, which is another feature of the Code.

(6) Regarding air conditioning and purification. This is the core content of the Code, mainly divided into four parts: systems, airflow organization, components and materials, and technical indicators.

In the systems part, the following points are worth noting:

1) Class I and Class II clean operating rooms should adopt independent purification air-conditioning units, and the fresh air may use a centralized supply system. 2) The system shall have at least three stages of filtration; the fresh air must be provided with three-stage filtration of coarse, medium, and sub-high efficiency. 3) In view of the importance of humidity control for operating rooms and the occurrence of nurses fainting in existing operating rooms, requirements on the fresh air treatment state and on the minimum fresh air volume for each operating room are put forward. 4) The exhaust of operating rooms should preferably be set up independently and switched on and off together with the supply air, so as to ensure the discharge of anesthetic and other gases.

In airflow organization: ① For the first time, it is explicitly proposed to arrange the air supply outlets in a concentrated manner above the operating table, and the area of the air supply outlet is given specifically based on theoretical calculations and with reference to domestic and foreign practice. This breaks through the usual practice in industrial cleanrooms of uniformly and dispersively arranging air supply outlets, and is conducive to obtaining a cleanliness level one grade higher with a small air volume and a bacterial concentration at least halved. The national review meeting evaluated this as "achieving a better cleanliness effect with less investment." ② To reduce cross-infection within the operating department, it is emphasized that operating rooms shall not return air to the corridor but shall recirculate their own return air. ③ For the first time, the arrangement principles for the final-stage high-efficiency filters in Class 100 clean zones are given, including the full coverage ratio and the ratio of the operating air volume to the rated air volume. This is very necessary for overcoming the past phenomena in Class 100 clean operating rooms of vague concepts, cutting corners, and serious hidden troubles, so as to ensure the quality of unidirectional flow (formerly called laminar flow), and it is also a major feature more detailed than foreign standards. ④ For the first time, it is proposed that an air supply face with a leak-blocking function may be adopted, with the filters arranged outside the static pressure box. This is significant for avoiding replacement and maintenance inside the room, overcoming the difficulty of insufficient storey height, improving the uniformity of the supply airflow, and raising the supply air of Class II and Class III from turbulent flow to close to laminar flow characteristics, all of which have obvious benefits.

For component materials, particular emphasis is placed on suitability for the requirements of medical purification systems. Around this point, the Code has given many specific provisions, bringing it closer to the concept of humidity-priority control and of reducing secondary microbial contamination caused by air-conditioning equipment and ducts. This provides an opportunity for China to take the lead in producing such air conditioners. Moreover, the specific design measures based on this concept have been accepted abroad, and this practice has been adopted in the newly formulated Swiss hospital standard.

Among the technical indicators, the Code has made specific provisions for several indicators in light of China's national conditions. For Class Ⅰ clean operating rooms, it specifies that the average cross-sectional air velocity in the operating zone at a height of 0.8m (without obstructions such as operating tables) or 1.05m (with obstructions such as operating tables) shall be 0.25～0.3m/s, and, proceeding from the maintenance of operational quality, it stipulates that the passing value for acceptance testing shall be no less than 0.27m/s. Also reflecting its distinctive features are the provisions on self-purification time and self-purification air change rate. For the first time, it is proposed that the self-purification time for back-to-back consecutive operations in an operating room should be taken into account, that this time should be shortened as much as possible to a reasonable range, and that the self-purification air change rate should be calculated and given accordingly. For operating rooms, this is slightly larger than the air change rate conventionally used in industrial cleanrooms, and the conventional value was originally aimed at dynamic indicators anyway, so it serves the purpose of rapid self-purification after dynamic operations. This not only has an effect in terms of purification performance, but also has economic significance in speeding up the turnover of operating rooms and bringing convenience to patients. Meanwhile, for rooms other than operating rooms, the self-purification air change rate is not needed. Considering that testing is now conducted in the static (at-rest) state, whereas the previously conventional dynamic air change rate was far too large, and that the current focus is on controlling bacterial concentration, a value smaller than the conventional air change rate has been given based on theoretical calculation and practice, so as to achieve savings. Furthermore, in view of the waste caused in the past by design and construction units unilaterally increasing air change rates, the Code for the first time gives not only the lower limits of air change rate and cross-sectional velocity, but also an upper limit of 1.2 times.

(7) On medical gases, water supply and drainage, and power distribution. This part embodies the principle of paying attention both to technical advancement and to safety. The Code stipulates that a modern clean operating department must have a centralized gas supply and must have backup devices. Based on accidents that have already occurred, it clearly points out that gas source connectors must not be interchangeable. It stipulates that the water supply must have two inlets; based on the actual conditions of operating rooms and with the consent of the fire department, it stipulates that sprinkler heads shall not be installed inside operating rooms. With regard to power distribution, it emphasizes that the main feeder line of each operating room shall be laid separately, that wireless communication equipment should not be used inside operating rooms, and that cardiac surgery operating rooms must be equipped with a functional grounding system with an isolation transformer; it also emphasizes that lighting fixtures are not allowed within the range of the air supply outlet, and so on. All of these are to ensure surgical safety.

(8) On fire protection. The Code devotes a dedicated chapter to fire protection, with its provisions substantially increased to 9 articles. There are clear provisions on fire resistance rating, fire doors, smoke control and exhaust, fire protection measures for technical mezzanines, and so on. It proposes that fire hydrants and sprinkler heads shall not be installed inside operating rooms, and that a device capable of emergency shut-off of the centralized oxygen supply main line shall be provided.

(9) On construction acceptance. Although the Code is not a construction code, provisions must be made on some major principles from the standpoint of ensuring overall comprehensive quality. Considering that construction of operating departments is currently quite chaotic, the Code emphasizes that the main construction contractor should exercise unified command in accordance with the construction sequence. Considering the situation in which acceptance after project completion lacked any rules—anyone would go and take measurements, and anyone could perform acceptance—the Code proposes two-stage acceptance, namely the completion acceptance between Party A and Party B, and the comprehensive performance evaluation and acceptance by a third party; it stipulates that the testing for the latter must be conducted by an authorized professional quality inspection institution. In order to unify testing standards, the Code has made specific provisions on the measurement methods for the mandatory test indicators.

(10) On appendices. One appendix of the Code concerns gas acceptance, which will not be further explained here.

Based on the above introduction and analysis, the implementation of the Standard and the Code will make the construction of hospital clean operating departments in China regularized, systematic, and standardized, and aligned with international standards, and their quality will achieve a qualitative leap.