Bench fume hood with horizontal sash - 14" working sash height. Bench fume hood with vertical sliding doors 14" working gap between doors

Transcription

1 UNIVERSITY OF HOUSTON ENVIRONMENTAL HEALTH AND SAFETY POLICIES AND PROCEDURES SECTION: SUBJECT: ENVIRONMENTAL HEALTH AND SAFETY LABORATORY FUME HOODS I. PURPOSE These laboratory fume hood survey procedures detail Environmental Health and Safety s (EHS) efforts to determine if the airflow rate is adequate for safe use by laboratory personnel. A fume hood is generally used in a laboratory as a safety device to provide local control and removal of airborne contaminants, ventilation, containment, shielding, or other uses. The proper operation of fume hoods is vital to the safety of the laboratory user. EHS will inspect all fume hoods as part of the regularly scheduled laboratory safety audit program. These procedures apply to all fume hoods located on the main campus as well as the College of Pharmacy located in the Texas Medical Center. II. PROCEDURES The fume hoods should be operated at the proper working sash height or door opening as follows: Bench fume hood with horizontal sash - 14" working sash height Bench fume hood with vertical sliding doors 14" working gap between doors Walk-in fume hood with horizontal doors determined by the needs of the specific investigator Walk-in fume hood with vertical doors determined by the needs of the specific investigator Plant Operations (PO) personnel make all corrective adjustments of the fume hood flow rates. In general, PO is responsible for routine maintenance and repair of the fume hoods. EHS will immediately report all fume hoods found to be deficient to PO this will normally be required due to a low flow rate. Other needed repairs, such as malfunctioning low-flow alarms or inoperative sashes or doors, should also be called-in by laboratory personnel when the repairs are needed. EHS may be required to determine if fume hoods are safe for PO personnel to work where chemicals or radioactive materials are used. A database of all fume hoods is maintained by PO. A PO number uniquely identifies each fume hood. EHS will use the PO number to refer to fume hoods in any instance if the fume hood number is known. Inspection dates and flow rates found during EHS surveys will be maintained by the EHS. However PO will have access to this information and be permitted to add it to their database. UH EHS 1

2 The following equipment is needed to perform the fume hood survey: 1. Hot wire anemometer or similar instrument to measure fume hood flow rates 2. Tape measure 3. Calculator 4. Fume Hood Air Velocity form 5. Yellow verification of measurement label with sash height arrow and black marking pen 6. Notice of Fume Hood Deficiency form The following measurement techniques are to be used: 1. All readings will be taken with the hot wire anemometer or similar instument. The anemometer is used to measure inward linear air velocity in ft/min on the same plane as the fume hood sash or doors (Example: face velocity). 2. Equally spaced air velocity readings will be taken based on a square foot grid system, using the Fume Hood Air Velocity Measurements form, as follows: Bench fume hood with horizontal sash sash at working height (normally between 14 and 18 ) Bench or walk-in fume hood with sliding doors consult with investigator for normal working opening Walk-in fume hood with horizontal sashes - consult with investigator for normal working opening 3. The average face velocity will be calculated by averaging the air velocity readings. Criteria used for satisfactory face velocity The target range of desired face velocities for conventional bench type fume hoods will be between fpm. As stated previously, walk in fume hoods will be handled on an individual basis with the specific investigator involved. Some of the newer laboratory buildings have low flow fume hoods that operate between fpm. The accepted criteria for these fume hoods will be the manufactures lowest operating range as indicated on the hood sticker. For fume hoods that don t meet the minimum flow rates, the following steps will be taken: o Immediately call the Physical Plant Customer Service Center (FIXIT) at to report the deficiencies. Write the Work Order number on a Fume Hood Deficiency Notice. o Make a copy of the Fume Hood Deficiency Notice for the inspection records. UH EHS 2

3 o Post the Notice of Fume Hood Deficiency on the fume hood. o The laboratory contact will be advised that the fume hood has failed the inspection and should not be used until repairs are completed by PO personnel. For fume hoods that fall in the target range, the following steps will be taken: o Record date, average face velocity, and initials of inspector on the yellow verification of measurement sticker. o Post the sticker at the working height of the fume hood. For fume hoods that exceed the target range, the following steps will be taken: o Record date, average face velocity, and initials of inspector on the yellow verification of measurement sticker. o Post the sticker at the normal working height of the fume hood. o EHS will then forward this information to the Facilities Management Group and request that the fume hood be brought into the desired range. III. REFERENCES ANSI/ASHRAE , Method of Testing Performance of Laboratory Fume Hoods. (1995 or most recent addition) Prudent Practices in the Laboratory: Handling and Disposing of Chemicals National Research Council, National Academy Press, Washington, D.C. (1995 or most recent edition) UH EHS 3

4 University of Houston NOTICE OF FUMEHOOD DEFICIENCY Building: Room No: Fume Hood ID Number: As part of the laboratory safety inspection program, this fume hood was surveyed by Environmental Health and Safety Department (EHS) personnel, and was found to have the following problem(s): Low Flow Rate No Flow (< 25 ft/min) Flow Blocked by Equipment Inside Flow Blocked by Equipment Outside Sash Inoperative Other This fume hood has been called-in by EHS personnel for repairs. THIS FUME HOOD SHOULD NOT BE USED UNTIL THE REPAIRS ARE COMPLETED BY PLANT OPERATIONS PERSONNEL AND THIS NOTICE HAS BEEN REMOVED BY PLANT OPERATIONS OR ENVIRONMENTAL HEALTH AND SAFETY PERSONNEL. For the status of fume hood repairs, contact the Pant Operations Customer Service Center at (FIXIT) or online at and then click on status Inspected by: Date: Work Order Number: UH EHS 4

5 University of Houston FUME HOOD FACE VELOCITY MEASUREMENTS Building: Room Number: Date: Check if after repairs Date: Fume Hood I.D. Number: Type of Fume Hood: Bench hood with horizontal sash Bench hood with sliding doors Walk-in with horizontal sashes Walk-in with sliding doors Other: Air Velocity Measurements for Bench Hood with Horizontal Sash at Working Height Average Air Velocity: ft/min PASS or FAIL (Work Order Number: ) Repairs needed: Low air velocity Low flow alarm doesn t sound Other: Additional Air Velocity Measurements if Needed Average Air Velocity: ft/min Comments: UH EHS 5