UNR Ventilation Policy

Transcription

1 UNR Ventilation Policy UNR Ventilation Policy

2 TABLE OF CONTENTS SECTION TITLE PAGE 1.0 Scope and Application Responsibilities EH&S Facilities Services Department End Users General Design Requirements Design HVAC Supply Quality HVAC Supply Volume HVAC Return Systems Make-Up Air Quality Make-Up Air Volume HVAC & Make-Up Air Distribution Minimum Number of Hoods Exhaust Discharge Exhaust Fans Exhaust Stacks Exhaust Gas Manifolding Emergency Backup Power Monitoring Devices Noise Levels Hood Design Requirements Design Selection Criteria Face Velocities Conventional Hoods Bypass Hoods Variable Volume Hoods Low Flow Constant Volume Hoods Auxiliary Supplied Air Hoods Perchloric Acid Hoods Perchloric Acid Hood Construction Walk-In Hoods Glove Box Hoods Work Practices & Performance Testing, & PM Exhaust System User Work Practices Exhaust System Monitoring Exhaust System Performance Testing Exhaust System Repairs Biological Safety Cabinet User Work Practices 18 UNR Exhaust Ventilation System Policy 2

3 5.2.1 Biological Safety Cabinet Certification Biological Safety Cabinet Repairs BSL3/4 Laboratory Performance Testing Preventative Maintenance Employee Training Laboratory Staff Recordkeeping, Labeling & Warning Signs Training Records Exhaust System Performance Testing Results Biological Safety Cabinet Certification Records BSL 3/4 Laboratory Performance Test Records Definitions References 25 UNR Exhaust Ventilation System Policy 3

4 UNIVERSITY OF NEVADA, RENO VENTILATION POLICY 1.0 SCOPE & APPLICATION This policy applies to all University of Nevada, Reno (UNR) operations or processes using hazardous chemicals/materials which are open to the work environment, and where faculty, staff, students, or the general public may be exposed. The purpose of this policy is fourfold: a. To minimize exposure risks to faculty, staff, students, and the general public by controlling airborne chemical emissions through proper application and use of HVAC and/or exhaust ventilation equipment. b. To prevent environmental insult by minimizing release of volatile compounds and application of appropriate air filtration and/or mechanical scrubbing technologies to remove particulate, organic, and radionuclides prior to environmental discharge. c. To ensure that mechanical components of HVAC and/or exhaust ventilation systems conform to accepted standards of design and practice and comply with current regulatory requirements and applicable standards. d. To establish operational requirements for the installation and use of HVAC and/or exhaust ventilation systems in UNR facilities. UNR Exhaust Ventilation System Policy 1

5 2.0 RESPONSIBILITIES 2.1 ENVIRONMENTAL HEALTH & SAFETY (EH&S) has the responsibility to: a. Develop, implement, and maintain the UNR Ventilation System Policy. b. Review HVAC and/or exhaust ventilation system designs for health and safety concerns during initial design phase and prior to new construction and renovation projects; this may include input on energy efficient designs, minimum exhaust air requirements, appropriate make-up air devices, and appropriate exhaust ventilation design parameters. c. Make recommendations for necessary and appropriate HVAC and/or exhaust ventilation system modifications or upgrades. d. Develop rules of use which establish safe work practices for the proper use of HVAC and or exhaust ventilation systems; including minimum exhaust air requirements. e. Identify and provide appropriate training programs for exhaust ventilation system users. f. Perform routine scheduled exhaust ventilation system performance assessments, including annual laboratory hood surveys. g. Respond to user complaints regarding EV system performance. UNR Exhaust Ventilation System Policy 2

6 2.2 FACILITIES SERVICES DEPARTMENT (FSD) has the responsibility to: a. Consult with EH&S during initial design phases of new construction and renovation projects to identify ventilation related health and safety concerns; this may include input on energy efficient designs, minimum exhaust air requirements, appropriate make-up air devices, and appropriate exhaust ventilation design parameters. b. Design, construct and install HVAC and exhaust ventilation systems, which follow, recognized standards and good practices. c. Design, construct and install exhaust ventilation systems which reduce exhaust air to the lowest, safe level as specified by EH&S. This may include the use of VAV hoods, approved high performance low-flow constant volume hood devices, the use of automatic sash lowering devices, and/or the VAV hood occupancy sensors. Consideration should be given to utilizing smaller or shared hoods. d. Include appropriate system performance monitoring devices and systems in all exhaust ventilation system design, construction, modification, up-grade, and repair plans. e. Construct all exhaust ventilation systems of structurally appropriate and chemically compatible materials. f. Provide adequate, contaminant free, make-up air to replace air exhausted by exhaust ventilation systems. UNR Exhaust Ventilation System Policy 3

7 g. Provide all necessary HVAC and system preventative maintenance, service, and repair support functions. 2.3 EXHAUST VENTILATION SYSTEM END USERS have the responsibility to: a. Ensure that chemicals and materials being used in exhaust ventilation systems are compatible with the exhaust ventilation system classification designation. b. Maintain exhaust ventilation sash position within the designated limits, as indicated by sash height stickers. c. Close exhaust ventilation sashes when the system is not used or unattended. d. Ensure that chemicals are not routinely stored within the exhaust ventilation system enclosure; all chemicals or wastes in exhaust ventilation system enclosures must be sealed tightly when not in use to minimize environmental escape. e. Contact EH&S personnel for evaluation or B&G personnel for repairs in the event of an exhaust ventilation system alarm indicating a system failure. f. Not disconnect or in any manner bypass or render inoperable exhaust ventilation system alarms. g. Maintain the interior of the exhaust ventilation system enclosure in a clean and unobstructed manner, keeping baffles and slots free of equipment or debris. UNR Exhaust Ventilation System Policy 4

8 h. Ensure that biological safety cabinets are properly certified as described in section 5 of this document; including the maintenance of records associated with biological safety cabinet certifications. 3.0 GENERAL DESIGN REQUIREMENTS 3.1 DESIGN: All HVAC, exhaust ventilation, and make-up air systems should be designed, constructed, and installed following applicable American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE), Sheet Metal and Air Conditioning Contractors National Association (SMACNA), Building Officials and Code Administrators (BOCA), Air Conditioning Contractors of America (ACCA) and local codes only by those personnel with proper education and credentials. Designs and modifications shall: a. Include appropriate operational status monitoring systems, such as static pressure sensors and alarms to notify users of unacceptable performance; b. Incorporate all feasible energy saving techniques while providing adequate user protection; and, c. Be approved by the EH&S Department and Facilities Services Department representatives prior to purchase, construction, installation, or retrofit. UNR Exhaust Ventilation System Policy 5

9 3.2 HVAC SUPPLY QUALITY: HVAC supply air shall meet the technical requirements of the work and the requirements of the latest version of ANSI/ASHRAE 62. Outdoor air shall be supplied to facilities in accordance with the latest version of ANSI/ASHRAE 62. HVAC supply air systems shall not introduce additional contaminants into the workplace HVAC SUPPLY VOLUME: The quantity and distribution of HVAC supply air should be sufficient to prevent the buildup of fugitive emissions in the workspace. Additional requirements for laboratory spaces are as follows: a. A minimum volume flow rate of 1 cubic feet per minute (cfm) per square foot of floor area or 6 air changes per hour (ACH) is required for general laboratory spaces during normal, nonhazardous laboratory operations. This rate may increase significantly during high hazard laboratory operations, spills, or for specific laboratory types. If the minimum volume flow rate is used, provisions must be made to provide an on demand increase to at least 12 air changes per hour during high hazard periods. b. A slightly negative differential air pressure should be maintained between laboratories and adjacent areas in order to contain fugitive vapors and odors within the laboratory. An inward air velocity of at least 50 fpm is required at all laboratory openings (fully opened). BSL3/4 laboratories require a minimum of to w.g. differential between the laboratory and adjacent areas. UNR Exhaust Ventilation System Policy 6

10 c. Where flow from one area to another is critical for emission and exposure control (such as BSL3/4 laboratories), airflow and/or static pressure differential monitoring devices with appropriate alarms will be installed HVAC RETURN SYSTEMS: HVAC air supplied to laboratories shall not be returned to the air handling systems for recirculation unless the following provisions are met: a. Return air meets the air requirements of ASHRAE 62; and b. There are no extremely dangerous or life threatening materials used in the laboratory, and the concentration of air contaminants generated by a maximum-credible accident will result in exposure concentrations below 20% of appropriate standards; or c. The return air is both treated and monitored to assure contaminant concentrations are below 20% of the appropriate standards at all times and under all conditions, and a by-pass is provided for diverting contaminated air to the atmosphere when necessary. 3.3 MAKE-UP AIR QUALITY: Make-up air shall meet the technical requirements of the laboratory work and the requirements of the latest version of ANSI/ASHRAE 62. Make-up air systems shall not introduce additional contaminants into the workplace. UNR Exhaust Ventilation System Policy 7

11 3.3.1 MAKE-UP AIR VOLUME: The air handling system will supply a volume of make-up air nearly equal to the volume exhausted by the exhaust ventilation system. A slightly negative differential air pressure should be maintained between laboratories and adjacent areas in order to contain fugitive vapors and odors within the laboratory. a. An inward air velocity of at least 50 fpm is required at all laboratory openings (fully opened). BSL3/4 laboratories require a minimum of to w.g. differential between the laboratory and adjacent areas. b. Where flow from one area to another is critical for emission and exposure control (such as BSL3/4 laboratories), airflow and/or static pressure differential monitoring devices with appropriate alarms will be installed. 3.4 HVAC & MAKE-UP AIR DISTRIBUTION: Supply air distribution will be designed, installed, and operated to create terminal velocities at the face of a hood which are less than 1/2 of the exhaust face velocity of the hood itself. Supply air should be injected at low velocity through an opening with large dimensions. 3.5 MINIMUM NUMBER OF LABORATORY HOODS: Where workers spend much of their time working with chemicals, at least one hood should be provided for every two workers. Each worker should have a minimum of 2.5 linear feet of working space at the hood face. UNR Exhaust Ventilation System Policy 8

12 3.6 EXHAUST DISCHARGE: Laboratory ventilation exhaust air shall be: a. Directed to the outdoor atmosphere. b. Discharged to avoid re-entrainment into building air-handling systems and to avoid hazards to the public. c. Labeled so that the connection between each exhaust ventilation system and its discharge is clear. d. Filtered as follows: 1. HEPA filtration for BSL 3/4 laboratories, where radiological particulates may be generated, or where toxic particulates may pose a risk to personnel or environments around the exhaust discharge; 2. Appropriate gas phase adsorption (such as activated charcoal) when radiological gaseous contaminants are generated or where toxic gas phase contaminants may pose a risk to personnel or environments around the exhaust discharge; 3. Provisions should be made for safe decontamination and removal of HEPA and/or gas phase adsorption filters (such as bag-in bag-out designs); 4. HEPA filters in BSL3/4 laboratory exhaust should have provisions for challenging and subsequent testing of filter performance. UNR Exhaust Ventilation System Policy 9

13 3.6.1 EXHAUST FANS: All exhaust fans shall be located exterior to the building, to ensure that the entire exhaust ventilation system will be under negative pressure in relation to the building interior EXHAUST STACKS: Esthetic considerations shall not supersede the requirements this section. Laboratory exhaust stacks shall meet the Sheet Metal and Air Conditioning Contractors National Association (SMACNA) and local codes and shall be: a. Discharged in a vertical-up position. b. Discharged a minimum of ten feet above any adjacent roof line and/or air intake(s) if located within 50 feet of the intake. c. Have a discharge velocity sufficient to avoid downwash during local high winds (at least 3000 fpm); exhaust velocity should not be achieved by installation of a cone type reducer EXHAUST GAS MANIFOLDING: Two or more exhaust systems may be combined into a single manifold and stack provided that the following conditions are met: a. Mixing of the gases will not result in reaction product likely to cause fire, explosion, excessive corrosion, or excessive condensation. b. The entire exhaust manifold is maintained under negative pressure at all times. UNR Exhaust Ventilation System Policy 10

14 3.7 EMERGENCY BACKUP POWER: Emergency backup power should be provided to all laboratory hood exhaust fans and associated control systems where possible; emergency backup power is required for critical exhaust fans, biological safety cabinets in BSL 3 & 4 laboratories, and HVAC systems in BSL 3/4 laboratories. 3.8 MONITORING DEVICES: All new or remodeled laboratory exhaust hoods shall be equipped with a real time performance monitor, preferably a hood-static pressure-monitoring device. 3.9 NOISE LEVELS: System design must provide for control of exhaust system noise (both fan and air generated noise). Systems must be designed to achieve an acceptable sound pressure level frequency spectrum; a noise criteria (NC) curve of 55 dba is generally adequate for a standard laboratory. 4.0 HOOD DESIGN REQUIREMENTS 4.1 DESIGN: Laboratory exhaust hoods shall be constructed of noncombustible, nonporous materials, which are selected to resist corrosion by the chemicals anticipated to be used in the hood. Hood sashes shall be made of laminated safety glass. Hoods shall be located away from high traffic areas, doorways, or other areas where air disturbance may cause a loss of containment. UNR Exhaust Ventilation System Policy 11

15 4.1.1 SELECTION CRITERIA: Laboratory exhaust hoods will be selected or constructed to minimize emissions and exposures. All new hoods shall meet the requirements be tested in accordance with ASHRAE Written results for each newly designed hood should be obtained from the manufacturer and provided to EH&S upon installation FACE VELOCITIES: Unless otherwise stated, laboratory exhaust hoods will maintain an average face velocity between 80 to 120 fpm, with the sash opening at 16. No individual face velocity measurement should exceed +/- 25% of the hood s average velocity; a face velocity deviation of greater than 25% will require a more detailed investigation as to the cause of the deviation. It is preferable that velocity measurements not exceed 10% of the hood s average face velocity. Measured face velocities for specific hood types are as follows: 4.2 CONVENTIONAL HOODS: Conventional hoods will meet the requirement of paragraph of this section. 4.3 BYPASS HOODS: Bypass hoods will meet all the requirements of Paragraph of this Section. As the sash is closed, the average face velocity shall not exceed 3 times the average face velocity when the sash is in the wide open position. UNR Exhaust Ventilation System Policy 12

16 4.4 VARIABLE VOLUME HOODS: Variable volume hoods will meet all the requirements of Paragraph of this Section. Exhaust volumes with the sash fully closed shall be at least 10% of full open face volume. Variable volume hoods will also modulate supply air to maintain the design pressure differential between the laboratory and adjacent spaces. Hood damper response times shall be less than three seconds over the complete operation range. 4.5 LOW FLOW, CONSTANT VOLUME HOODS: High performance low flow, constant volume hoods must have a minimum inward average face velocity of 60 linear fpm and must meet and be initially tested in accordance with ASHRAE All low flow, constant volume hoods must be approved by EH&S with written authorization. 4.6 AUXILIARY-SUPPLIED AIR HOODS: New auxiliary-supplied air hoods will not be installed. Existing auxiliary-supplied air hoods shall meet the following provisions: a. The supply plenum will be located above the top of the hood and external to the hood. b. The supply jet will be uniformly distributed across the width of the hood. c. Airflow will be into the hood at all points across the hood face. d. Face velocities shall be measured with the supply air turned off. UNR Exhaust Ventilation System Policy 13

17 4.7 PERCHLORIC ACID HOODS: Perchloric acid laboratory hoods will meet all the requirements of Paragraph of this Section and will also conform to the requirements of NFPA 45, Paragraph Heated perchloric acid shall be used only in a dedicated and approved hood; each hood shall be labeled For Perchloric Acid Operations Only. The following conditions of use shall apply to all perchloric acid laboratory hoods: a. Organic materials shall not be used in perchloric acid designated fume hoods. b. Perchloric acid use shall be kept to a minimum and controlled at the source, where feasible. c. Perchloric acid and perchlorates shall not be allowed to be permanently deposited in the exhaust ventilation system PERCHLORIC ACID HOOD CONSTRUCTION: a. Perchloric acid laboratory hoods, ductwork, and exhaust fans shall be constructed of acid resistant, non-reactive materials (such as 316 stainless steel) which are impervious to perchloric acid. b. The exhaust fan should be acid and spark resistant. The exhaust fan and drive belts should not be located within the ductwork. c. All joints shall be sealed with gaskets and sealants that are acid resistant and non-reactive with perchloric acid; flexible connectors will not be used. d. All perchloric acid laboratory hoods, duct work, and fan systems shall be equipped with a water wash down system; duct work shall UNR Exhaust Ventilation System Policy 14

18 provide an appropriate drainage slope back into the hood; the hood work surface shall be watertight with an 1/2 inch dished front and sides; and an integral trough provided at the rear of the hood shall be provided to collect wash-down water. e. The hood baffle shall be removable for inspection and cleaning and the hood surface should have an all-welded construction with rounded corners to facilitate cleaning. f. All utility controls for perchloric acid exhaust ventilation systems should be mounted to the outside of the hood. g. Perchloric acid exhaust systems shall not be manifolded or joined to non-perchloric acid exhaust ventilation systems. 4.8 WALK-IN HOODS: Walk-in laboratory hoods shall comply with all provisions of Paragraph of this Section. The base of a walk-in laboratory hood shall provide for spill containment having a base contiguous with the sidewalls and a vertical lip of at least 1-inch in height. 4.9 GLOVE BOX HOODS: Where possible, utility controls for glove box hoods shall be external. Glove boxes will have provisions for the complete containment of the maximum volume of material to be used. Exhaust ventilation shall be provided for glove boxes which: a. Maintain a static pressure difference of 0.1 inches water gauge (w.g.), with respect to the room; UNR Exhaust Ventilation System Policy 15

19 b. Maintains at least 100 fpm inward face velocity when the largest port is open or at the glove port should the glove fail; and c. Is filtered or scrubbed and discharged to the atmosphere. 5.0 Work Practices, Performance Testing, & Preventative Maintenance 5.1 EXHAUST SYSTEM USER WORK PRACTICES: Exhaust ventilation system users will establish work practices to minimize emissions and exposures. Such practices shall include the following: a. Prohibit storage of chemicals in the exhaust ventilation system enclosure when chemicals are not in use. b. Keep slots and baffles free from obstructions. c. Raise large equipment at least 1.5 off the hood surface. d. Conduct all work at least six (6) inches back from the forward edge of the exhaust ventilation system enclosure. e. Prohibit users from placing heads and/or upper body inside the exhaust ventilation system enclosure while procedures involving volatile emissions are under way. f. Minimize placement of hood sashes outside acceptable performance zone as indicated by sash height stickers. g. Keep sashes closed when hood is not in use. h. Avoid rapid movements at the hood face. i. Minimize foot traffic in the vicinity of the hood. UNR Exhaust Ventilation System Policy 16

20 5.1.1 EXHAUST SYSTEM PERFORMANCE MONITORING: Each new or remodeled laboratory exhaust hood shall be equipped with a real time performance monitor, such as a hood-static pressure-monitoring device. Existing hoods that do not have a real time performance monitor shall be equipped with a kimwipe or light string hanging from the sash in order to provide the user assurance that the system is operating properly EXHAUST SYSTEM PERFORMANCE TESTING: Exhaust ventilation systems shall have be performance tested at least annually and following any system modification or repair. The exhaust system performance test procedure shall be as follows; a. Performance tests shall be conducted using a calibrated air velocity-measuring instrument such as a velometer, a vane anemometer, or a hot wire anemometer. b. Tests should be performed by opening all sashes associated with a given exhaust fan to 16. c. Performance tests shall consist of an average of multiple face velocity measures collected at evenly spaced intervals across the exhaust ventilation system face. d. Standard laboratory hoods will require a minimum of nine (9) velocity measures. The number of velocity measurements shall not be less than three (3). UNR Exhaust Ventilation System Policy 17

21 e. Resultant face velocity measurements shall meet the criteria set forth in Section 4 of this document. f. Hoods shall be visually smoke tested to determine if the containment capability of the hood is adequate for its intended use EXHAUST SYSTEM REPAIRS: All repairs to exhaust ventilation systems shall be completed as soon as feasible; users should be notified of repair system status; EH&S shall be notified upon completion of repairs. 5.2 BIOLOGICAL SAFETY CABINET USER WORK PRACTICES a. Ready Work Area turn off UV lamp (if equipped) turn on fluorescent light check air grilles for obstructions turn on fan (blower) & allow air to purge workspace for 3 minutes b. Pre-Disinfect spray or swab all interior surfaces with an appropriate disinfectant & allow the surfaces to air dry c. Assemble Materials only introduce materials that are required to perform the procedure position materials so that clean and contaminated items do not touch contaminated items downstream of clean items ensure the view screen (sash) is properly located and secured d. Pre-Purge Cabinet allow the BSC fan to run for at least three minutes with no activity inside (leave fan on) e. Prepare Self don protective clothing, gloves, mask, etc., as appropriate. f. Perform Procedures minimize movement of arms during procedure; move arms straight in or out of the BSC when entering or exiting. work from a clean area to more contaminated work areas UNR Exhaust Ventilation System Policy 18

22 g. Cleanup and Post-disinfection remove gloves into contaminated material container place potentially contaminated materials in a biohazard bag or other appropriate container wipe surfaces of all items in the BSC with an appropriate disinfectant remove all items from the BSC and autoclave (or otherwise disinfect) waste and other contaminated materials as appropriate disinfect all surfaces of the BSC h. Personal Hygiene remove protective clothing, mask, etc., and dispose of as appropriate wash hands i. Post-Purge Cabinet allow air purge period (minimum of three minutes) with no activity inside (leave fan on) j. Shutdown Cabinet turn off blower and fluorescent lamp turn on UV lamp (if equipped) BIOLOGICAL SAFETY CABINET CERTIFICATION: Field certification of biological safety cabinets in accordance with National Sanitation Foundation (NSF) criteria is required under the following circumstances: upon installation of a new BSC, annually thereafter, after repair or maintenance is performed, and after relocation of the BSC. Field certification tests shall include: a. Inflow Test b. Downflow Test c. Smoke Pattern Test d. HEPA Filter Leakage UNR Exhaust Ventilation System Policy 19

23 e. Cabinet Leakage (when BSC is newly installed, relocated, or maintenance has been performed that involved removal of access panels) Additional tests performed at discretion of certifier should include: a. Noise/Vibration b. Lighting c. Electrical leakage, polarity, and ground circuit resistance BIOLOGICAL SAFETY CABINET REPAIRS: In most cases, biological safety cabinets requiring repair shall be repaired by a qualified cabinet certifier. 5.3 BSL 3/4 LABORATORY PERFORMANCE TESTING a. Balance HVAC supply and exhaust; negative pressure differentials of at least water gauge should be maintained in the BSL3 laboratory when doors are closed. A minimum inward velocity of 50 fpm is required in open doorways. b. Certify operation of biological safety cabinets and performance of any facility HVAC HEPA filters c. Verify that HVAC, critical exhaust fans, and biological safety cabinets are on backup power; document time it takes for backup power to activate. d. Simulate failure of BSL3/4 air handling unit (turn entire unit off); check for loss of room containment as described in this section. UNR Exhaust Ventilation System Policy 20

24 e. Simulate failure of critical exhaust fans (disable air handling unit exhaust fan /or other critical exhaust fans). An interlock between supply and exhaust fan shall exist which deactivates the supply fan in the event of an exhaust fan failure. Check for loss of room containment as described in this section. f. Perform smoke test and document pressure gauge readings to evaluate the ability of system to maintain negative pressure during: normal operation, power failure, BSL3/4 air handling unit failure, and critical exhaust fan failure. The smoke test should include passing smoke over all doorways and/or openings associated with the BSL3/4 laboratory to visually assess inward flow. 5.4 PREVENTATIVE MAINTENANCE: A preventative maintenance program will be established for each EV, HVAC, and make-up air system; preventative maintenance will be performed on a regularly scheduled basis. 6.0 EMPLOYEE TRAINING 6.1 LABORATORY STAFF: All members of laboratory staff whose duties include the use of laboratory hoods shall receive training which covers the following (See Checklist, Appendix A): a. Back Baffle & Slot Blockage b. Location of Work within Hood UNR Exhaust Ventilation System Policy 21

25 c. Conditions Associated with Containment Loss d. Housekeeping Requirements e. Hood Sash Operation & Position f. Appropriate Hood Face Velocities g. Flow Monitoring Device Operation h. Assessment of Hood Operational Status i. Qualitative and Quantitative Hood Evaluations 7.0 RECORDKEEPING, LABELING AND WARNING SIGNS 7.1 TRAINING RECORDS: Records of all exhaust ventilation system related training should be maintained in the departmental employee files for which training was conducted. 7.2 EXHAUST SYSTEM PERFORMANCE TESTING RESULTS: Records should be maintained of all exhaust ventilation system monitoring and testing. Exhaust ventilation system performance monitor records should be maintained at the hood location. Annual and routine airflow testing results shall be maintained with the EH&S Department. 7.3 BIOLOGICAL SAFETY CABINET CERTIFICATION RECORDS: Records should be maintained of all biological safety cabinet certification testing and/or maintenance with each cabinet by the cabinet user. UNR Exhaust Ventilation System Policy 22

26 7.4 BSL3/4 LABORATORY PERFORMANCE TESTING RECORDS: Records should be maintained by the laboratory; copies of all records, including HVAC balancing reports, shall be provided to the EH&S Department. 8.0 DEFINITIONS ACGIH: the American Conference of Governmental Industrial Hygienists. AIHA: the American Industrial Hygiene Association. Balancing: designing the EV system to provide appropriate static pressures and volume flow rates or adjustments made after construction to system components (e.g., dampers, fan speeds) to assure proper pressures and flow rates throughout the system. Biological Safety Cabinet (BSC): a term for three classes of enclosures similar to laboratory hoods with an inward airflow through the front opening designed to provide protection from biological particulates and aerosols; exhaust air from most biological safety cabinets is passed through a HEPA filter to provide protection for the worker and the public; supply air to the work surface is also often passed through a HEPA filter to protect the research material from contamination Biological Safety Level 3 Laboratory (BSL3): a laboratory where work is performed with indigenous or exotic agents that may cause serious or potentially lethal disease as a result of exposure by the inhalation route; this type of laboratory requires a specialized facility which is further defined in the latest version of CDC/NIH Biosafety in Microbiological and Biomedical Laboratories. Biological Safety Level 4 Laboratory (BSL4): a laboratory where work is performed with exotic agents that pose a high individual risk of aerosol transmitted laboratory infections and life-threatening disease; this type of laboratory required highly specialized containment systems which are further defined in the latest version of CDC/NIH Biosafety in Microbiological and Biomedical Laboratories. Exhaust Ventilation: the use of directional ventilation to capture and control emissions, odors, and chemical exposure hazards in equipment, processes, and operations in UNR facilities; local exhaust ventilation UNR Exhaust Ventilation System Policy 23

27 includes devices such as laboratory hoods, task exhausts, canopy hoods, slotted hoods and glove boxes. Face Velocity: means the rate of flow per square area (e.g., cfm/ft 2 of enclosure open face area), or the velocity (feet per minute) of air moving through an enclosure opening. Gas Cabinet: a metal enclosure, which is intended to provide fire protection for the gas cylinder in the cabinet; most indoor gas cabinets are supplied with EV capable of controlling leaks but not catastrophic cylinder failures. Glovebox Hood : an enclosed six-sided hood with arm-length stretch gloves provided at the front or side of the hood for access. An air-lock pass-through port is often provided to insert and remove materials. Hood : a device which captures, contains, or controls a chemical emission by the use of air flow through the hood and may include conventional laboratory hoods, canopy hoods, slotted hoods, task exhausts, glove boxes or other configurations which are designed to control airborne emissions. Hood Static Pressure: the static pressure near a hood, measured 2-5 duct diameters downstream in the duct near the hood. HVAC (Heating, Ventilating, and Air Conditioning): air-handling systems designed to provide control of temperature, humidity, and air quality. Make-Up Air: air supplied to a space to replace exhausted air Manometer: a device used to measure pressure differences, usually a U- shaped glass tube containing water, oil or mercury. Plenum: a low velocity air chamber used to distribute static pressure throughout its interior; used with slotted hoods and exhausted enclosures. Pressure Drop: the loss of static pressure across a specified point Scrubbing : a device designed and operated to remove air contaminants from the air stream; a laboratory hood modified for use with perchloric acid, for example, may incorporate water scrubbers and wash down devices. STP: standard temperature and pressure. At STP, ACGIH considers air to weigh lbs/ft 3. Static Pressure, (SP): the pressure developed by a fan; SP exerts influence in all directions; the force in inches of water measured perpendicular to the flow at the wall of the duct; the difference in pressure between atmospheric UNR Exhaust Ventilation System Policy 24

28 pressure and the absolute pressure inside a duct, cleaner, or other equipment. Volumetric Flow Rate (Q): the volume or quantity of air flowing per unit of time, expressed as cubic feet per minute (cfm) or cubic meters per second (cms). 9.0 REFERENCES ACGIH Industrial Ventilation, A Manual of Recommended Practice, 24 th edition. AIHA/ANSI Z , Laboratory Ventilation ANSI/AHSRAE , Standard Methods for Laboratory Airflow Measurement ANSI/ASHRAE , Ventilation for Acceptable Indoor Air Quality ANSI/ASHRAE , Method of Testing Performance of Laboratory Fume Hoods CDC/NIH Biosafety in Microbiological and Biomedical Laboratories NSF/ANSI , Class II Laminar Flow Biosafety Cabinetry OSHA 29 CFR , Flammable and Combustible Liquids OSHA 29 CFR , Occupational Exposure to Hazardous Chemicals in Laboratories UNR EH&S Ventilation Hood Survey Procedure UNR Exhaust Ventilation System Policy 25