16.4.2 Fume Hood Applications
Fume hood applications: This does not apply to highly toxic and toxic compressed gases, in cylinders large than 20ft3 at STP due to the face velocity requirements.
- The smallest possible cylinder should be used for the experiment (a six-month bottle supply for routine use gases is appropriate, while smaller cylinder supplies are suggested for short term use);
- Cylinders of toxic and highly toxic gases that are 20 ft3 or smallerat NTP are allowed within fume hoods as long as there are no incompatible materials also used in the hood or storage of any items inside.
- Make an effort to obtain gas cylinders in returnable bottles;
- Order bottles with lowest cylinder pressure possible;
- Use a flow restricting orifice or needle valve to restrict flow to only that needed for the experiment;
- Consider using a dilution of the gas that is suitable for the research, but falls outside of the New York State code requirements;
- Place the cylinder in rear of the hood. High pressure leaks can readily escape the hood and capture is best in the rear of the hood;
- Assure all components in experiment can withstand full bottle pressure or incorporate pressure relief (run relief line into a hood slot);
- All gas lines connected to the hazardous gas source, including purge lines and gas supply lines, must be completely contained inside of the hood. If this is not possible, the cylinder must go into a gas cabinet.