§ 627.51 - Class II biological safety cabinet.

All Class II biological safety cabinets (figure H-II in appendix F to this part) are ventilated cabinets for personnel and product protection, having an open front with inward air flow for personnel protection.

(a) Operating standards. (1) All of these cabinets must conform and be certified to meet National Sanitation Foundation (NSF) Standard No. 49 revised, June 1987, for the applicable type of cabinet.

(2) After installation and before use, and annually thereafter, the cabinets will be tested in accordance with NSF Standard No. 49 (latest revision June 1987) as follows:

(i) Primary (required) tests—

(A) Velocity profile test.

(B) Work access opening airflow (face velocity) test.

(C) HEPA filter leak test.

(D) Cabinet integrity test (soap bubble test) for cabinets with positive pressure internal plenums.

(ii) Secondary (optional) tests—

(A) Vibration test.

(B) Electrical leakage and ground circuit resistance tests.

(C) Noise level test.

(D) Lighting intensity test.

(E) UV light intensity test.

(3) After repairs or alterations to the cabinetry or ventilation system that affect the cabinet, the tests listed in § 627.51(a)(2) will be performed for the relevant parameters.

(4) The work access opening airflow (face velocity) test, as specified in NSF Standard No. 49 (latest revision, June 1987), will be performed to check that the cabinet is within specifications on an annual basis for BL-1 and BL-2 and toxin use. This test will be performed semiannually on cabinets used for BL-3 and BL-4 as well as for work with dry forms of toxins.

(5) When the exhaust is recirculated in a BL-4 facility, the cabinet must be tested and certified semiannually.

(b) Class IIA biological safety cabinets.—(1) Description. A Class IIA biological safety cabinet is one in which typically 70 percent of the air is recirculated within the cabinet and the exhaust passes through a HEPA filter before discharge. The exhaust may be exhausted into the room and positive-pressure contaminated ducts and plenums within the cabinet are allowed. Type A cabinets shall have a minimum calculated face velocity of 75 feet per minute (fmp).

(2) Uses. These cabinets are for working with low-to-moderate risk biological samples and for protecting personnel against biological material while providing a sterile atmosphere in which to handle the material.

(3) Prohibitions. Materials that are toxic or volatile must not be used in these cabinets.

(c) Class IIB1biological safety cabinets.—(1) Description. A Class IIB1 biological safety cabinet is one that maintains a minimum average inflow of air of 100 plus or minus 20 lfpm and in which typically 30 percent of the air is recirculated. All recirculated and exhausted air passes through two HEPA filters in series. All contaminated internal ducts and plenums are under negative pressure. Type B cabinets shall have a minimum calculated face velocity of 100 fpm.

(2) Uses. When ultra-sterility is needed, these are the cabinets of choice. The double filtration achieves a cleaner atmosphere. Minute quantities of volatile, toxic, or volatile radioactive materials coincidental to use in biological systems may also be used in these cabinets.

(3) Prohibitions. More than minute quantities of toxic, volatile, or radioactive materials must not be used in these cabinets.

(4) Additional certifications or requirements. None.

(d) Class IIB2biological safety cabinets.—(1) Description. A Class IIB2 biological safety cabinet is one that maintains a minimum average of 100 plus or minus 20 lfpm inward flow and in which all air is exhausted directly from the cabinet through a HEPA filter without recirculation within the cabinet. All contaminated ducts and plenums are under negative pressure. Type B cabinets shall have a minimum calculated face velocity of 100 fpm.

(2) Uses. These cabinets are recommended when small quantities of volatile, flammable, or toxic chemicals must be used coincidentally with items requiring sterility.

(3) Prohibitions. While these cabinets do offer the greatest degree of safety for volatile, toxic, and flammable chemical handling in a sterile environment, they are not to be used in place of a fume hood to prepare stock solutions of hazardous chemicals.

(e) Class IIB3biological safety cabinets.—(1) Description. A Class IIB3 biological safety cabinet is one that meets all of the requirements of a Class IIB2 biological safety cabinet except that it recirculates most (typically 70 percent) of the air inside the cabinet. Type B cabinets shall have a minimum calculated face velocity of 100 fpm.

(2) Uses. Minute amounts of nonflammable chemicals can be used coincidentally with low-to-moderate risk biological agents.

(3) Prohibitions. Flammable materials and more than minute amounts of toxic, radioactive, or volatile chemicals must not be used in these cabinets.

(4) Additional certifications or requirements. None.