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Guidelines Part 30

Guidelines Part 30 Contents

GENERAL REQUIREMENTS

  G30.4 Plumbing
  G30.8 Fume hoods
  G30.9 Airflow monitoring
  G30.12 Biological safety cabinets
  G30.13 Centrifuges

SPECIFIC SUBSTANCES AND PROCEDURES

  G30.29 Electrophoresis

Guidelines Part 30 - General requirements

G30.4 Plumbing

Issued August 1999

Section 30.4(1) of the OHS Regulation requires that laboratory water faucets with goosenecks be protected by vacuum breaks. These vacuum breaks must meet the requirements of ANSI Standard ANSI/ASSE 1001-1990 (Pipe Applied Atmospheric Type Vacuum Breakers) or other standard acceptable to the board. Other standards acceptable to the board include the BC Plumbing Code and CSA Standard CAN/CSA-B64.7-94, Vacuum Breakers, Laboratory Faucet Type (LFVB).

The BC Plumbing Code requires that connections to potable water systems be designed and installed so that substances that may render the water non-potable cannot enter the system. In addition, the BC Plumbing Code also requires premises or zone isolation for laboratory facilities where a potentially severe health hazard may be caused by back flow.

The purpose of a vacuum break is to prevent back-siphoning of contaminated water into the potable water supply used for eyewash heads, emergency showers, other laboratory sinks, or other services outside the laboratory when a hose or tubing is attached to the faucet. The most common back-siphon prevention device for laboratory gooseneck faucets is an atmospheric type vacuum break. This vacuum break is not designed for continuous pressure applications and so is installed after the last control valve. An in-line pressure type vacuum break may be installed to prevent back-siphoning simultaneously at several sinks so long as back-siphoning into any part of a potable water system is prevented and the device supplies the same level of protection as a faucet-mounted atmospheric type vacuum break. Such a device would possibly be installed at a location not immediately visible to workers. The location of the device should be clearly identified and communicated to workers.

G30.8 Fume hoods

Issued August 1999; Editorial Revision February 1, 2008

Regulatory excerpt
Section 30.8(2) of the OHS Regulation ("Regulation") states:

A laboratory fume hood must
    (a) be connected to a local exhaust ventilation system,
    (b) provide average face velocities of 0.4 m/s (80 fpm) to 0.6 m/s (120 fpm) across the operational face opening,
    (c) not have face velocities of less than 80% of the average face velocity required in paragraph (b) at any point across its operational face opening, and
    (d) not have face velocities of more than 120% of the average face velocity required in paragraph (b) at any point across its operational face opening.

And section 30.8(3) of the Regulation states:

A laboratory fume hood must be located to prevent cross drafts or other disruptive forces from lowering the air flow across the operational face opening to unacceptable levels.

Purpose of guideline
The purpose of this guideline is to explain measures that may be taken by small laboratories or mobile laboratories that may have difficulties meeting the requirements of section 30.8(2) and 30.8(3).

Small laboratories and mobile laboratories
Sections 30.8(2) and 30.8(3) of the Regulation respectively specify minimum air flows and placement considerations for laboratory fume hoods. These sections may present special challenges for small laboratories or mobile laboratories, where, because of their size and inadequate air balancing, air flows through the fume hood may be significantly affected by wind conditions, and open or shut doors. To minimize disturbances of airflow patterns, the employer may need to

  • Develop more detailed and more restrictive safe work procedures
  • Implement more administrative controls, such as one worker in the lab at a time
  • Implement engineering controls, such as double air-lock doors

Where the fume hood is still susceptible to significant cross-drafts and pressure changes despite the implementation of control measures and workers are at risk of exposure to harmful materials, the employer may need to continuously monitor the airflow in the hood. Particular care must be taken with the distribution of replacement air and movement of personnel in small laboratories. Horizontal sashes can offer better containment and splash protection than vertical sashes.

A ventilation system must be balanced to ensure that the desired airflow is or can be delivered and to accommodate typical or anticipated occupancy rates. Balancing is the process of adjusting the system, such as by altering damper positions or changing fan speed, to deliver the right amount of air at the right temperature to each space, or to provide additional make-up air to compensate for the exhausted air. The outdoor air requirements for a given indoor space will vary depending on the occupant density and the activities performed. When determining if a system is properly balanced, typical occupancy rates need to be considered. Refer to Table 2 of ASHRAE Standard 62-1989 for guidance. The building may be fully occupied (close to design standards), partially occupied (significantly below design standards), or unoccupied (no workers or only a skeleton staff on duty). Note that even if the building is considered to be "unoccupied," the requirements for controlling exposure in Part 5 apply if contaminants are being generated, such as during the use of janitorial products by one or more workers after normal business hours.

If the temperature, carbon dioxide concentration and humidity level stay within acceptable ranges, the system is balanced. There is nothing to be gained by measuring airflow if the system is controlling these parameters.

G30.9 Airflow monitoring

Issued August 1999; Revised November 17, 2003; Editorial Revision February 1, 2008

Regulatory excerpt
Section 30.9 of the OHS Regulation ("Regulation") states:

(1) Face velocities over the operational face opening of a laboratory fume hood must be quantitatively measured and recorded.

(2) The ability of a laboratory fume hood to

    (a) maintain an inward flow of air across the operational face opening, and
    (b) contain contaminants
must be assessed and recorded using a smoke tube or other suitable qualitative method.

(3) The actions described in subsections (1) and (2) must be performed

    (a) after the laboratory fume hood is installed and before it is used,
    (b) at least once in each 12 month period after installation, and
    (c) after any repair or maintenance that could affect the air flow of the hood.

(4) If a laboratory fume hood is found to be operating with an average face velocity of less than 90% of the average face velocity required in section 30.8 (2), the employer must immediately take corrective action to bring the average face velocity within the required range of velocities.

(5) Airflow in a laboratory fume hood must be monitored continuously if loss of airflow will result in risk to a worker.

(6) A laboratory fume hood that is being installed must have an alarm capable of indicating when the average face velocity falls below the minimum average face velocity level required in section 30.8 (2) when the hood is in use.

Purpose of guideline
The purpose of this guideline is to provide information about techniques to measure average face velocity. The guideline also discusses 'continuous monitoring' under section 30.9(5).

Measuring face velocity
Section 30.8(2) of the Regulation specifies fume hood exhaust ventilation rates in terms of air velocities measured over the operational face area of the hood. The operational face area is determined by the height of the sash and will vary with the work carried out in the fume hood. Section 30.9 contains rules for measuring and recording airflow.

The average air velocity is generally calculated by taking the average of measurements made over at least 6 points at the operational face of the hood with the sash raised to its highest position. If the measured average velocity is less than specified in section 30.8, repeat measurements should be made with the sash lowered successively until both the specified average air velocity, and the minimum acceptable air velocity are attained. The sash height where this is determined should be marked. A mechanical stop should be installed to prevent the sash from being raised beyond that point. The sash height should not be less than 30 centimeters (12 inches). If the minimum acceptable air velocities cannot be attained with the above procedure, modification should be made to improve the ventilation so the specified air velocities are maintained at the sash height required for the work performed.

When a sash height adjustment is necessary on a fume hood, which is part of a manifold system (several hoods serviced by a single exhaust fan), all fume hoods in the system should be rechecked at completion of all the adjustments to ensure face velocity compliance. This operation may have to be repeated several times before compliance is achieved.

Smoke tube tests will help to determine whether conditions of air turbulence exist at the face of the hood. If these conditions exist so that air spills out past the hood face, the condition should be corrected.

Continuous monitoring or airflow
Where there is a risk to workers in the event of loss of airflow, section 30.9(5) requires that the employer continuously monitor the airflow in a fume hood if loss of air flow would result in risk to the worker. In the context of this section, "continuous monitoring" should include both the continuous measurement of airflow through the hood or duct (usually by measuring duct static pressure or air speed) and a notification to workers of low-flow by way of an alarm, light, or other effective means. The employer should develop a safe response procedure to the alarm.

G30.12 Biological safety cabinets

Issued August 1999; Editorial Revision February 1, 2008

Regulatory excerpt
Section 30.12(2) and 30.12(3) of the OHS Regulation ("Regulation") states:

    (2) Biological safety cabinets must be certified by a qualified person at least annually and before use after
      (a) initial installation,
      (b) change of the HEPA (high efficiency particulate air) filter,
      (c) moving of the unit, and
      (d) any repair or maintenance that could affect the seal of the HEPA filter.
    (3) Certification procedures used for compliance with subsection (2) must meet the requirements of the National Sanitation Foundation (NSF) Standard 49-2002, Class II (Laminar Flow) Biohazard Cabinetry, and a record of the results must be maintained.

Purpose of guideline
The purpose of this guideline is to specify another acceptable standard under section 30.12(2). The guideline also discusses the term 'qualified person' and the field certification requirements for biological safety cabinets.

Other acceptable standard
Under sections 30.12(2) and 30.12(3) of the Regulation, a qualified person must certify biological safety cabinets in accordance with the requirements of National Sanitation Foundation (NSF) Standard 49-2002, Class II (Laminar Flow) Biohazard Cabinetry. Another acceptable standard is CSA Standard Z316.3-M87, Biological Containment Cabinets: Installation and Field Testing.

Qualified person
The definition of "qualified" is provided in section 1.1 of the Regulation. For the purpose of section 30.12(2), a "qualified person" is a person with knowledge, training, and experience in certification of biological safety cabinets. For example, one combination of knowledge, training, and experience that would be acceptable to WorkSafeBC would be a person who has been accredited by the National Sanitation Foundation to perform testing of biological safety cabinetry.

Field certification requirements
The field (as opposed to factory) certification requirements for biological safety cabinets are listed in Annex F of the NSF standard. The tests that make up these requirements include

  • Downflow velocity profile test
  • Inflow velocity test
  • Airflow smoke patterns
  • HEPA filter leak test
  • Cabinet leak test (required when a cabinet is first installed, if it is relocated, or after maintenance procedures that require removal of the panels)
  • Electrical leakage, ground circuit resistance, and polarity tests
  • Lighting intensity test
  • Vibration test
  • Noise level test

A cabinet that meets the test criteria should have the following information visibly posted on the cabinet:

  • Date of certification
  • Date cabinet should be recertified (stated as no later than a specified date)
  • Number of the certifier's report (a reference document showing the tests performed and the results. WorkSafeBC would accept an alternative means of readily locating the certifier's report, such as the serial number of the cabinet)
  • Name, address, and telephone number of the certifying company
  • Signature of the qualified person who performed the field certification tests
G30.13 Centrifuges

Issued August 1999

Under section 30.13(3), the employer must ensure that centrifuge doors are interlocked, unless exempted by CSA Standard C22.2 No. 151-M1986. The CSA standard requires an interlock on a centrifuge where Emax exceeds 1 kiloJoule. For these centrifuges, the catch must be locked in the engaged position when the motor is energized and it must remain locked until the energy level drops to 1 kiloJoule or less.

For centrifuges where Emax is less than 1 kiloJoule, a readily accessible lever or knob can be used for releasing the catch, so long as it is designed to minimize the chance of unintentional operation. The CSA standard requires that, where a lever or knob is provided for releasing the catch on an access of a centrifuge, the following warning statement must be prominently marked adjacent to the lever or knob:
WARNING: DO NOT OPEN THE ACCESS COVER UNTIL THE HEAD HAS STOPPED

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Guidelines Part 30 - Specific substances and procedures

G30.29 Electrophoresis

Issued August 1999

Section 30.29(1) of the OHS Regulation requires that electrophoresis equipment be designed and maintained so that any hazardous electrical current is shut off when the cover is opened. For the purpose of this section, "hazardous electrical current" is any current that is large enough to startle a worker. Even low levels of current may startle a worker and cause an inadvertent action. WCB Engineering Update 91-15 describes the effects of electrical current on the human body.

The cover referred to in this section is any physical barrier that prevents access to any hazardous electrical energy during operation. In some commercial electrophoresis systems, this may be the cover of the sample tray or carrier; in other systems, the cover may be over an electrolyte solution or gel.

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Disclaimer: The Worker and Employer Services Division issues Guidelines to help with the application and interpretation of sections of the Occupational Health and Safety Regulation and with divisions of the Workers Compensation Act that relate to health and safety. Guidelines are not intended to provide exclusive interpretations but to assist with compliance. WorkSafeBC ("Workers' Compensation Board of B.C.") does not warrant the accuracy or the completeness of the online version of the Guidelines and neither WorkSafeBC nor its board of directors, employees or agents shall be liable to any persons for any loss or damage of any nature, whether arising out of negligence or otherwise, which may be occasioned as a result of the use of the online version of the Guidelines.