Non-Tariff Barriers

Non-Tariff Measure

NTM classification

B7: Product quality, safety or performance requirements 

Date when the measure came into force

02 April 2001 

Publication where the measure is specified

Government Notice R93 (Government Gazette 22014) Of 2 February 2001 

Regulation where the measure is specified

Compulsory Specification For Microbiological Safety Cabinets (Classes I, II And III) 

Country/Region applying the measure

South Africa 

The rationale of the measure

1.1 This specification covers requirements for the construction, fittings and pre-installation and post- installation performance of class I, class li and class III microbiological safety cabinets (also known as biological safety cabinets) intended to protect the operator and the environment from hazardous microbiological materials and (if so required by the customer or user or both), organic toxins and non-corrosive volatile organic agents.

NOTE - Microbiological safety cabinets are not intended to provide protection against corrosive chemical or radioactive materials.

1 .2 The specification does not cover the actual design of a safety cabinet and in no way restricts new design, provided that a microbiological safety cabinet of a new design complies with the requirements for materials, reliability, performance and safety given in this specification.

NOTE - Microbiological safety cabinets of class I, class II and class III should not be confused with laminar flow
clean workstations that usually discharge horizontally and vertically towards the operator and that do not provide
protection for an operator, but can even increase exposure to airborne hazards. 

Coded list of objectives

X: For purposes n.e.s. 

Description of the measure

4.2 Class 11 cabinets

4.2.1 General

4.2.1.1 A class II cabinet shall be a self-contained unit that includes at least a work space, prefilters, HEPA-filters and a blower for unidirectional (laminar) HEPA-filtered airflow and HEPA-filtered exhaust air. If handling of organic toxins and non-corrosive volatile organic agents is required, an activated carbon filter shall also be included.


4.2.1.2 The cabinet shall be independent operating unit, and shall be independent of any other air- circulation system
4.2.1.3 The exhaust outlet may face in any direction, provided that it is readily accessible.

4.2.1.4 The work face of the work space shall include a viewing window and a work-access aperture through which an inward flow of air is maintained.

4.2.1.5 In order to contain potentially hazardous materials within the cabinet, all contaminated zones under positive air pressure shall be surrounded by zones maintained under a negative pressure relative to the pressure in the work room/environment.

4.2.1.6 The delivery area for the air to the work space shall be free from interposed projections or cavities that could interfere with the containment performance.

4.2.1.7 When a class II cabinet is tested in accordance with 6.5.3.1, the DOP aerosol penetration at all construction joints bordering the work space shall not exceed 0,03 %.

4.2.2 Work floor
The work floor shall be firm, shall not be fastened and shall be readily raised but shall have a location- fixing and position-fixing system, as well as systems to prevent reversed installation. The work floor may be solid or perforated. If the work floor is solid, it shall have a retaining lip around Its perimeter of height at least 10 mm, that serves to contain spillage of liquid within the cabinet. All corners of the floor shall be radiused to facilitate cleaning and disinfection (see 3.4.2). Components or attachments associated with the work floor in the work space shall be so constructed as to facilitate easy and effective cleaning and disinfection.

4.2.3 Sump
The sump, which provides the base of the lower air plenum, shall be watertight and all joints shall be welded, ground flush and dressed. The sump shall be sized to retain fluid to a depth of at least 10 mm. The floor of the sump shall be free from obstructions and attachments, and have all corners radiused to facilitate cleaning and disinfection (see 3.4.2). The sides of the lower air plenum (i.e. the area below support structures for the work floor) shati be free from cracks, crevices and sharp projections that could adversely affect cleaning and disinfection.
4.2.4 Flow and distribution of air
4.2.4.1 Recirculating air and air barrier
Air shall be recirculated through the work space through HEPA-filters and in a unidirectional (laminar) manner, thus providing contamination-free air for product protection.

An air barrier between the work space and the room shall be created across the full width of the work- access aperture by the induction of atmospheric (room) air downwards into the sump.

4.2.4.2 Velocity and uniformity of airflow in the work space
4.2.4.2.1 When determined in accordance with 6.6.3.2, the average velocity of the unidirectional (laminar) flow of air shall be not less than 0,45 m/s and not more than 0,50 m/s. No single velocity reading shall differ from the average velocity by more than 20 %.

4.2.4.2.2 When a cabinet is tested in accordance with 6.10, the total number of colonies of the test organism, counted after incubation, shall not exceed five in any of the six replicate tests, thus indicating a minimum of cross-contamination and, therefore, an acceptable level of uniformity of airflow.

4.2.4.3 Air barrier integrity
4.2.4.3.1 When a cabinet is tested in accordance with both 6.5 and 6.1 0, the DOP aerosol penetration shall not exceed 0,03 %, and the number of colonies of the test organism counted on the plates shall not exceed five in any test.
4.2.4.3.2 When a cabinet is tested in accordance with 6.8. the cabinet shall offer a protection factor of at least 1 ,0 X 10^5

4 2 4 3 3 The mean inward airflow velocity at the work-access aperture shall be at least 4 m/s when indirectly measured as exhaust airflow velocity in accordance with 6.6.3.2.2. This shall be achieved at the minimum specified downward airflow velocity of 0,45 m/s in the work space.

4 2 4 3.4 When a smoke test is carried out in accordance with 6.5.3.3, it shall indicate that the direction of airflow is inwards over the whole area of the work-access aperture.

NOTE - The proportional adjustment of the quantities of barrier air and the work space air is critical to the performance of the cabinet, as is the unidirectional (laminar) flow of the air within the cabinet.

4 2 4 3.5 When a smoke test is carried out in accordance with 6.5.3.3.2, it shall visually indicate that there is no escape of smoke to the ambient side over the whole area of the work-access aperture. In addition, there shall be no undue turbulence which could lead to backstreaming along the inside of the window.

4.2.4.4 Temperature
The temperature, measured inside the cabinet at a height of 100 mm above the centre of the work space, shall not rise by more than 8 °C above the ambient temperature in the laboratory after 4 h of continuous working of the motor blower (see 3.6) and the lights turned on. 

Reference of the measure

Regulation 4.2 

Measure also domestic

Yes 

Products affected by the measure.

Description

Microbiological safety cabinets in class II 

Countries/Regions affected by the measure.

Description

All countries