Document ZnG7OR2OeoG6D0nDxYJM6XeL

May 30, 1991 Dow U.S.A. The Dow Chemical Company P O Box 150 Plaquemine, Louisiana 70765 0150 Dean Walters Cell Service Building 5601 On May 30, 1991, AT-500 and conveyor In the Cell Service Block, Building 5601, was checked for face velocity. The Alnor Model 8925 Thermo Anemometer was used to take the face velocity measurements. AT-500 was checked at a(n) 24 " sash opening. The criteria for hood classification, smoke tube observation, and flow measuring devices used in rating hood ventilation performance is attached. Also included are recommendation(s), observation(s), testing data sheet(s) and a maintenance checklist which should be followed to maintain effective hood ventilation and appropriate classification. Please respond in writing to Industrial Hygiene within one month as to action taken or planned in regard to these recommendations. Please feel free to contact me with any questions. Thank you, Darlene S. Creel Industrial Hygiene Department Building 3502-W Ext. 6181 DO A 07F8R0 OONFTDFNT T Al Page 2 Observations: The laboratory hood designation, the average face velocity (FV) and minimum measurements (FVm) reported in feet per minute (FPM), and its rated classification is as follows: DesignationSash Hood Opening AT-500 24 " (FPM) FV 163 (FPM) FVm____ Classification 125 The smoke turbulence was good on AT-500. Cm/EVOR The smoke turbulence was GOOD. Recommendations: 1. AT-500 and conveyor should be put on C-9 checklist for annual check and routine maintenance done on them 2. Practice good housekeeping inside the AT-500. no a OONF T DFNT T A1 Page 3 CRITERIA FOR HOOD CLASSIFICATION. SMOKE TUBE OBSERVATION. AND FLOW MEASURING DEVICES CLASSIFICATIONS: CLASS "A" (HIGH TOXICITY USE) CARCINOGENIC, TOXIC HIGHLY FLAMMABLE 125-150 FT/MIN AVERAGE FACE VELOCITY 100 FT/MIN MINIMUM READING CLASS "B" (MODERATE TOXICITY USE) TOXIC OR FLAMMABLE 100 FT/MIN AVERAGE FACE VELOCITY 80 FT/MIN MINIMUM READING INADEQUATE DOES NOT MEET MINIMUM REQUIREMENTS SMOKE TUBE OBSERVATIONS: ""GOOD (AIR CAPTURE BY HOOD IS STRONG AND WELL DEFINED WITH MINIMAL INTERNAL TURBULENCE, AND NO OBSERVABLE SMOKE SWIRUNG BACK TO HOOD FACE WHEN PERSON STANDS AT HOOD FACE.) ""MODERATE (AIR CAPTURE BY HOOD IS POSITIVE BUT WITH SOME INTERNAL TURBULENCE OBSERVED APPROACHING THE HOOD FACE. NO SMOKE ESCAPING THE HOOD.) ""POOR (AIR CAPTURE BY HOOD IS WEAK AND/OR NOT WELL DEFINED. TURBULENCE INSIDE THE HOOD AND SMOKE OBSERVED ESCAPING HOOD FACE.) ELQW MEASURING. DEVICES: WHEN THE STATIC PRESSURE DEVIATES (-/+) 10% FROM THE LISTED STATIC PRESSURE, ITEM #20 SHOULD BE FOLLOWED ON THE MAINTENANCE CHECKUST ATTACHED TO THIS REPORT. THE STATIC PRESSURE READING WAS ESTABLISHED AT TIME OF PERFORMANCE CHECK AND INDICATED BY A RED UNE ON THE DEVICE. DOCUMENTATION OF AIR FLOW MONITOR DEVICE PERFORMANCE IS TO BE DONE ONCE PER WEEK. INSPECTION/ZEROING/CAUBRATION OF AIR FLOW DEVICE IS TO BE DONE ONCE PER YEAR. THIS DOCUMENTATION IS TO BE PART OF THE INDUSTRIAL HYGIENE RECORDS FOR YOUR PLANT. PLEASE FORWARD DOCUMENTATION TO THE PLANT INDUSTRIAL HYGIENE CONTACT FOR YQUR PLANT. DO A OONFTDFNTTAt PAGE 4 LOUISIANA DIVISION INDUSTRIAL HYGIENE HOOD PERFORMANCE TESTING DATA PLANT: Cell Service HOOD I.D.: AT-500 DATE: May 30, 1991 TESTED BY: Darlene Creel CONVEYOR---smoke observation was GOOD. HOOD FACE VELOCITY READINGS AT A(N) 24" SASH OPENING. |125 193| |160 119| SMOKE TUBE OBSERVATIONS WITH A(N) 7A" SASH OPENING - ****GOOD (AIR CAPTURE BY HOOD IS STRONG AND WELL DEFINED WITH MINIMAL INTERNAL TURBULENCE, AND NO OBSERVABLE SMOKE SWIRLING BACK TO HOOD FACE WHEN PERSON STANDS AT HOOD FACE.) (FPM)(FPM) DesignationSash Hood Opening______________________ EY_____EYm___Classification AT-500 24 " 163 125 Used the Alnor Model 8925 Thermo Anemometer FV = AVERAGE FACE VELOCITY FVm = MINIMUM MEASUREMENT FPM = FEET PER MINUTE DO A 023883 CONFIDFNT T Al I CONSEQUENCES OF EXPOSURE TO TOXIC AMOUNTS f NOISE ACUTE: Short exposure to high noise levels may cause ringing in the ears ana/or temporary hearing loss. Potential for aamage increases as sound pressure levels increase above 90 dBA. Repeated short-term exposures may cause permanent loss. CHRONIC: Repeated exposures may destroy hair cells which transmit sound signals to the brain and may cause permanent hearing loss. Degree of hearing loss determined by sound level (dBA) & exposure time. Average dBA % of exposed workers with hearing loss at end of working lifetime 80 85 90 . 0-5 10-15 21-29 Typical sound pressure levels (dBA) Situation quiet room window air conditioner noise requiring you to raise voice to be heard at 3 feet, power lawn mower saws, grinders sand blasters CQNFTDFNTT A( pneumatic chipper or nail driver DOW CONFIDENTIAL {CAS 8/89 Page