Description
General requirements for clean air and clean rooms in hospitals
Modern requirements for clean rooms in medicine are established by GOST R 52539-2006 "Clean air in hospitals. General requirements" and SanPiN 2.1.3.2630-10 "Sanitary-epidemiological requirements for organizations engaged in medical activities." Regulatory documentation defines the requirements for clean rooms in hospitals, depending on the purpose and the operations performed in them.
Classification of clean rooms in medical institutions
Table 1. Classification of premises of medical institutions
Group of premises Purpose
1 High-aseptic operating rooms with unidirectional air flow.
2 Chambers of intensive care with unidirectional air flow
3 Operating rooms without unidirectional air flow or with unidirectional air flow with a smaller cross-sectional area than for rooms of group 1
Rooms with high purity requirements without unidirectional air flow
4 Rooms that do not require special measures to protect the patient, staff and other patients
5 Premises for infected patients (isolators)
Operating rooms for patients with purulent infection, patients with an anaerobic infection, etc., in which areas with unidirectional air flow with a cross section of 3.0-4.0 m2 should be provided.
For most of the premises of medical institutions, with the exception of the general-purpose chambers and ancillary facilities, there are special requirements for clean air.
Table 2. Basic requirements for clean indoor air in the equipped state
The group of premises The maximum allowable number of particles in 1 m3 of air (particles with a size of 0.5 μm) Room purity class according to GOST ISO 14644-1-2002
1 Operating table area 3520 5 ISO
The area surrounding the operating table 35200 6 ISO
2 Bedside of the patient 3520 5 ISO
The area surrounding the bed of the patient 35200 6 ISO
3 * 3520000 8 ISO
4 is not standardized -
5 * 3520000 8 ISO * If there is a zone with unidirectional air flow, the requirements for it correspond to the requirements for clean air in the area of the operating table (group 1)
Why carry out certification of clean rooms in medical institutions?
Testing of clean rooms of medical institutions in accordance with GOST R ISO 14644-3-2007 is necessary in order to confirm that clean rooms, after completion of construction or reconstruction, meet the requirements of regulatory documents and can be operated in accordance with their purpose. Practice shows that during testing, inconsistencies can be identified and quickly resolved, for example, with errors made during installation of structures and filters in clean rooms, or improper adjustment of the heating, ventilation and air conditioning systems of a medical institution. The inconsistencies associated with errors made in the design, unfortunately, most often impossible to quickly resolve.
Parameters determined during certification of clean rooms in medical institutions
In addition to the concentration of aerosol particles and the cleanliness class of the room, other parameters are also monitored in the premises of the hospital: the speed of unidirectional air flow, pressure drop between adjacent zones of different cleanliness class (or speed of air displacing air), microclimate parameters (temperature and humidity), outdoor flow rate (supply) air and air exchange rate. For rooms with unidirectional air flow, in which air is supplied through laminar ceilings with HEPA finish filters, the integrity of the installed filtration system can also be monitored.
Tests of clean rooms in medical institutions:
Concentration of particles with sizes> 0.5 µm
Room cleanliness class (separately for the room and the area of the operating table in the presence of unidirectional air flow)
Unidirectional airflow rate in the presence of a laminar zone
Air temperature
Relative humidity
Stability maintain temperature and humidity (if necessary)
Pressure drop between zones of different cleanliness classes
Air flow rate
Filter integrity (if necessary)
How is the certification of clean rooms in medical institutions?
As with the validation in the pharmaceutical industry, the mandatory test in clean medical premises is to verify that the cleanliness class of the premises complies with the established requirements. When this control is carried out on particles with sizes> 0.5 microns.
Measurement of particle concentration for a zone with unidirectional air flow is carried out in flow section planes perpendicular to the direction of air flow at a distance of 30 cm from the surfaces of filters (laminarizers) and at a distance of 30 cm from the upper surface of the operating table (bed) and the table for tools. At the same time, if the integrity control of the filters by the scanning method is provided, GOST R 52539-2006 allows for measuring the concentration of particles only
at a distance of 30 cm from the upper surface of the operating table (patient's bed) and the table for instruments.
Although checking the integrity of the installed filtration system is not a mandatory test according to GOST R 52539-2006, we recommend that it be carried out at the initial stage of room certification, as this allows identifying damaged and incorrectly installed filters, replacing them, and avoiding problems when measuring the cleanliness class.
In operating rooms and other premises where air quality is ensured by means of a unidirectional air flow, the velocity of the unidirectional flow is measured and its uniformity is assessed. In accordance with GOST R 52539-2006, the measurement of the speed of a unidirectional air flow should be carried out at a distance of 10 to 30 cm from the surface of the finishing filters:
The speed of a unidirectional air flow is determined at a distance of 10-30 cm from the surface of the filter (laminarizer). Measurement points should be evenly distributed over the cross-section of the air flow at a distance of at least 0.5 m from each other. The number of points must be at least four.
Since the method of determining the laminar flow velocity, given in GOST R ISO 14644-3-2007, regulates the conduct of measurements at a distance of 15 to 30 cm, measurements are usually carried out at a distance of 15 cm from the surface of the filters. Depending on the method used for the separation of clean zones with different purity classes, a measurement of pressure drops between adjacent rooms or a measurement of the velocity of the displacing flow can be carried out.
Control of microclimate parameters is another mandatory parameter for testing clean rooms in medical institutions. Measurements are carried out for an hour at the surface of the operating table.
GOST R 52539-2006 regulates the measurement of air flow and air exchange rate in the constructed state, while GOST R ISO 14644-3-2007 allows combining certification in the constructed and equipped states. In practice, this means that there is no need to separately measure the flow rate and frequency of air exchange in the constructed state, and then, after installing medical equipment and furniture, test the clean rooms according to other parameters.
Report on the testing of clean rooms in medicine
The report on the testing of clean rooms in medicine includes test reports and, if necessary, test reports with all primary data and calculations.
