Guidelines for care & Use of Dry Solvent Stills [Example]

It cannot be overemphasized that the hoods in Salem Hall were designed to maintain all
chemical exposures at levels below the permissible exposure limits (PELs) established by OSHA.
When used properly, only accidents and spills will result in overexposures to chemicals.
All research hood sashes have been replaced with “safety glass”. This glass will break into
literally hundreds of relatively small round non-lacerating bits of glass when cracked during use. If
explosions occur, the glass will actually partially absorb the shock in the process of breaking. When any
breakage occurs, replacements are kept in room #8A. Please call Physical Facilities (phone #4255) for
installation.
The research hoods have been physically placed in the room so as to minimize the effects of
traffic, i.e., walking in front of the hoods. Laboratory workers should nevertheless recognize that this
causes a certain amount of turbulence in front of the hoods and disrupts the flow of air. Fumes will
momentarily stretch outward from the hood if such traffic is severe. The air flow through the open sash is
maintained at 100 feet per minute while the speed of walking is about 3 miles per hour (or 250 feet per
minute). There is no law stipulating a certain air flow rate in the hoods, but it required that we adhere to
published standard recommendations, as follows (As advised by Dr. Haugen, we will adhere to NFPA 45
and ANSI/AIHA Z9.5 standard recommendations, for flow rates between 80 and 120 feet per minute – We
keep the research lab hoods set at 100 feet per minute):
PUBLISHED FACE VELOCITY RECOMMENDATIONS
Compiled by Dr. Bob Haugen, (Kewaunee Scientific Corporation, Laboratory Division, PO Box 5400,
Statesville, NC 28687, phone # 704-871-3214):
Organization Citation Face Velocity
1) ACGIH Industrial Ventilation 19 th edition p.5.24 60-100 FPM
2) ASHRAE 1999 ASHRAE Handbook, 13.5 20%-50% of exterior
disturbance velocities. (60-
175 FPM) if 300 FPM
walkby used to calculate)
3) ANSI/AIHA ANSI/AIHA Z9.5, Sect 5.7 80-120 FPM
4) CALOSHA CCR Title VIII, Subchapter 7.5454.1 Min 100 FPM
5) Nat. Rsrch.Cnc. Prudent Practices, p.178 80-100 FPM
6) NFPA NFPA 45: 6-4.5 & A6-4.5 "Sufficient to prevent
escape from hood; 80-120
FPM;
40 CFM/lin foot min
7) NIOSH Recommended Indust. Ventil. Gudelines p166 100-150 FPM
8) NRC NRC Guide, 6.3 100 FPM for hospital
radioactives
9) OSHA 29 CFR 1910 Appendix A Sec. A.C.4.g 60-100 FPM
10) SEFA SEFA 1.2: 5.2 75-100 FPM
54