Poison Gases

Poison gases represent a significant hazard. Specialprecautions not otherwise necessary become prudent when using poison gases:

• Common poison or highlytoxic gases include:

- arsine (AsH3)
- ethylene oxide (EtO)
- hydrogen cyanide (HCN)
- nitric oxide (NO)
- phosphine (PH3)

• Certain poison gases (e.g.,Ethylene Oxide) can only be used if specific OSHA regulations and safepractices are followed.

• Certain poison gases (e.g.,Ethylene Oxide) can only be used if specific OSHA regulations and safepractices are followed.

• Emergency procedures shouldbe made clear to all involved, including personnel from adjacent labs andbuilding managers.

• Poison gas use after normalworking hours require the approval of the Chemical Hygiene Officer for yourdepartment.

• Fume hoods and otherventilation need to be tested before use and checked frequently during theproject involving poison gas.

• Notify EnvironmentalHealth, Safety and Risk Management before your first use of the poison gas.

• The University Policeshould also be informed about the locations and types of poison gas in use.

• Document these proceduresin your lab's chemical hygiene plan. As with all chemicals, obtain and reviewthe Material Safety Data Sheet (MSDS) for the poison gas. Maintain an extracopy of the MSDS in your department's chemical hygiene plan. 

Cylinder Using

• Be sure all connections aretight. Use soapy water to locate leaks.

• Keep cylinders valves,regulators, couplings, hose and apparatus clean and free of oil and grease.

• Keep cylinders away fromopen flames and sources of heat.

• Safety devices and valvesshall not be tampered with, nor repairs attempted.

• Use flashback arrestors andreverse-flow check valves to prevent flashback when using oxy-fuel systems.

• Regulators shall be removedwhen moving cylinders, when work is completed, and when cylinders are empty.

• Cylinders shall be used andstored in an upright position.

• The cylinder valve shouldalways be opened slowly. Always stand away from the face and back of the gaugewhen opening the cylinder valve.

• When a special wrench isrequired to open a cylinder or manifold valve, the wrench shall be left inplace on the valve stem when in use; this precaution is taken so the gas supplycan be shut off quickly in case of an emergency; and that nothing shall beplaced on top of a cylinder that may damage the safety device or interfere withthe quick closing of the valve.

• Fire extinguishingequipment should be readily available when combustible materials can be exposedto welding or cutting operations using compressed cylinder gases.

Things Not To Do

• Never roll a cylinder tomove it.

• Never carry a cylinder bythe valve.

• Never leave an opencylinder unattended.

• Never leave a cylinderunsecured.

• Never force improperattachments on to the wrong cylinder.

• Never grease or oil theregulator, valve, or fittings of an oxygen cylinder.

• Never refill a cylinder.

• Never use a flame to locategas leaks.

• Never attempt to mix gasesin a cylinder.

• Never discard pressurizedcylinders in the normal trash.