| Product Name: | Hydrogen, Compressed |
| Chemical Name: | Hydrogen |
| Formula: | H2 |
| Chemical Family: | Flammable gas |
| Use: | Various |
| NFPA Fire: | 4 |
| NFPA Health: | 0 |
| NFPA Reactivity: | 0 |
| NFPA Special Hazard: | SA |
| HMIS Fire: | 4 |
| HMIS Health: | 0 |
| HMIS Reactivity: | 0 |
| Mixture: | No |
| Acute: | No |
| Chronic: | No |
| Fire: | Yes |
| Reactive: | No |
| Sudden Release Pressure: | Yes |
| Ingredients – Composition Information |
| Component: | Hydrogen |
| CAS No. | 1333-74-0 |
| Percent (by weight) | 99.0% 100.0% |
| ACGIH – STEL | Simple Asphyxiant |
| Emergency Overview |
| Danger: | Flammable, High Pressure Gas Can form explosive mixtures with air Burns with an invisible flame. |
| Potential Health Effects Information |
| Inhalation: | Asphyxiant. It should be noted that before suffocation could occur, the lower flammability limit of hydrogen in air would be exceeded; possibly causing both an explosive and oxygen-deficient atmosphere. Exposure to moderate concentrations may cause dizziness, headache, nausea and unconsciousness. Exposure to atmospheres containing 8-10% or less oxygen will bring about unconsciousness without warning, and so quickly that the individuals cannot help or protect themselves. Lack of sufficient oxygen may cause serious injury or death. |
| Eye: | None. |
| Skin: | None. |
| Ingestion: | None. |
| Carcinogenicity: | Not listed in NTP, OSHA or IARC |
| First Aid Measures |
| Inhalation: | |
| Remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get immediate medical attention. |
| Eye: | None. |
| Skin: | None. |
| Ingestion: | None. |
| Notes To Physician: | None. |
| Fire Fighting Measures |
| Flash Point: | Flameable Gas. |
| Auto ignition: | 565.5°C (1050°F) |
| Flammable Limits – Lower: | 4% |
| Flammable Limits – Upper: | 74% |
| Extinguishing Media: | CO2, dry chemical, water spray or fog for surrounding area. Do not extinguish until hydrogen source is shut off. |
| Fire Fighting Instructions: | Evacuate all personnel from danger area. Immediately cool container with water spray from maximum distance, taking care not to extinguish flames. If flames are accidentally extinguished, explosive re-ignition may occur. Stop flow of gas if without risk while continuing cooling water spray. |
| Hazardous Combustion Products: | None |
| Sensitivity To Static Discharge: Ignitable by static electricity |
| Sensitivity To Mechanical Impact: | None |
| Accidental Release Measures |
| Evacuate: | Evacuate immediate area. Eliminate any possible sources of ignition, and provide maximum explosion-proof ventilation. Shut off source of hydrogen, if possible. If leaking from cylinder, or valve, contact your supplier. The presence of a hydrogen flame can be detected by approaching cautiously with an outstretched straw broom to make the flame visible. Never enter a confined space or other area where the concentration is greater than 10% of the lower flammable limit which is 0.4%. |
| Handling and Storage |
| Storage: | Specific requirements are listed in NFPA 50A. Cylinder storage locations should be well-protected, well-ventilated, dry, and separated from combustible materials. Cylinders should never knowingly be allowed to reach a temperature exceeding 125°F (52°C). Cylinders of hydrogen should be separated from oxygen cylinders or other oxidizers by a minimum distance of 20 ft., or by a barrier of non-combustible material at least 5 ft. high having a fire resistance rating of at least ½ hour. Full and empty cylinders should be segregated. Use a first-in, first-out inventory system to prevent full containers from being stored for long periods of time. |
| Handling: | Do not “crack” hydrogen cylinder valve before connecting it, since self-ignition may occur. Hydrogen is the lightest gas known and may collect in the top of buildings with out proper ventilation. It may leak out of a system which is gas-tight for air or other gases. Leak check system with leak detection solution, never with flame. If user experiences difficulty operating cylinder valve, discontinue use and contact supplier. Never insert an object (e.g., wrench, screwdriver, pry bar, etc.) into valve cap openings. Doing so may damage valve, causing a leak to occur. Use an adjustable strap wrench to remove over-tight or rusted caps. Never strike an arc on a compressed gas cylinder or make a cylinder a part of an electrical circuit. Non-sparking tools should be used. For additional precautions in using hydrogen see Section 16 |
| Exposure Control – Personal Protection |
| Engineering Controls: |
| Ventilation: | Provide adequate natural or explosion-proof mechanical ventilation to ensure hydrogen does not reach its lower explosive limit of 4% |
| Personal Protective Equipment (PPE): |
| Skin Protection: |
| Clothing: | Cotton clothing is recommended for use to prevent static buildup. |
| Glasses: | Safety glasses are recommended when handling cylinders. |
| Shoes: | Safety shoes are recommended when handling cylinders. |
| Gloves: | Work gloves are recommended when handling cylinders. |
| Physical and Chemical Properties |
| Physical State: | Gas |
| Color: | Colorless gas. |
| Odor: | Oderless |
| Molecular Weight: | 2.016 |
| Boiling Point: | -423.0°F (-252.8°C) @ 1 atm |
| Specific Gravity: | .0696 At 32°F (0°C) @ 1 atm, Air = 1 |
| Freezing/Melting Point: | -434.55°F (-259.2°C), @ 1 atm |
| Vapor Pressure: | Not Applicable |
| Vapor Density: | .00521 lb./cu ft (0.08342 kg/CuM), At 70°F (21.1°C) @ 1 atm |
| Water Solubility: | .019 Vol./Vol at 60°F (15.6°C) |
| Expansion Ratio: | Not Applicable – Gas |
| pH: | Not Applicable – Gas |
| Odor Threshold: | None |
| Evaporation Rate: | Not Applicable – Gas |
| Coefficient Of Water/Oil Distribution: | Information not available |
| Stability and Reactivity |
| Chemical Stability: | Stable |
| Hazardous Polymerization: | Will not occur |
| Ecological Information |
| Ecotoxicity: | No adverse ecological effects are expected. Hydrogen does not contain any Class I or Class II Ozone depleting chemicals (40 CFR Part 82). Hydrogen is not listed as a marine pollutant by DOT (49 CFR Part 171). |
| Disposal Considerations |
| Waste Disposal Method: | Do not attempt to dispose of residual or unused quantities. Return cylinder to supplier. |
| Residual product within process system may be vented at a controlled rate, to the atmosphere through a vent stack that discharges to an elevated point. This vent stack should be in an isolated area away from ignition sources. |
| Transport Information |
| DOT/IMO Shipping Name: | Hydrogen, compressed. |
| Hazard Class: | 2.1 (Flammable gas.) |
| Identification Number: | UN 1049 |
| PIN: | 1049 |
| Product RQ: | None. |
| Shipping Label: | Flammable Gas. |
| Special Shipping Information: | Cylinders should be transported in a secure position, in a well ventilated vehicle. The transportation of compressed gas cylinders in automobiles or in closed-body vehicles can present serious hazards and should be discouraged. |
| Placard (When Required): | Flammable gas. |