Toxic gas cylinder storage at the University of Houston is regulated by the UH General Laboratory Safety Manual. 

Toxic gas cylinders listed here must be kept in a continuously, mechanically ventilated enclosure. Additionally, all compressed gas cylinders having a NFPA Health Hazard Rating of 3 or 4 (e.g. ammonia, chlorine, phosgene) and those with a Health Hazard Rating of 2 but no physiological warning properties (e.g. carbon monoxide) must be kept in a gas cylinder cabinet. EHS can help you determine the Health Hazard Rating of your compressed gases.

Full size cylinders must be stored in a gas cylinder cabinet while smaller cylinders, e.g., lecture bottles, can be stored in a chemical fume hood, a storage cabinet under the fume hood (if ventilated), or some other ventilated enclosure. No more than two small cylinders should be stored in single cabinet. When stored in a cabinet or hood, small cylinders must be positioned and secured so that they will not fall out and be fixed to a stationary object.

Compressed gas cylinder cabinets must meet NFPA 55 and the following requirements: 

• Negative pressure in relation to the surrounding area with the exhaust from the cabinet going to the outside of the building
• Self-closing doors
• Internally sprinklered or installed in a sprinklered area.

Cylinders stored in gas cylinder cabinets or other ventilated enclosures must be secured at all times. Cylinders should be firmly secured at their center of gravity, not near the top or bottom.

Hazardous gases include, but are not limited to:

• Acetylene
• Ammonia
• Arsenic Pentafluoride
• Arsine
• Boron Trifluoride
• 1,3 - Butadiene
• Carbon Monoxide
• Carbon Oxysulfide
• Chlorine
• Chlorine Monoxide
• Chlorine Trifluoride
• Chloroethane
• Cyanogen
• Diborane
• Dichloroborane
• Dichlorosilane
• Dimethylamine
• Ethane
• Ethylamine
• Ethylene Oxide
• Fluorine
• Formaldehyde
• Germane
• Hydrogen Chloride, anhydrous
• Hydrogen Cyanide
• Hydrogen Fluoride
• Hydrogen Selenide
• Hydrogen Sulfide
• Methylamine
• Methyl Bromide
• Methyl Chloride
• Methyl Mercaptan
• Nitrogen Oxides
• Phosgene
• Phosphine
• Silane
• Silicon Tetrafluoride
• Stibine
• Trimethylamine
• Vinyl Chloride