The primary safety hazards of hydrogen are fire (and the resulting burns since a hydrogen fire is not easily visible) and explosion if the hydrogen is compressed in a cylinder.
It is difficult to suffocate in hydrogen, although not impossible, because the gas is very light, rises to the ceiling, and easily exfiltrates through seams and small fissures in structures.
Hydrogen is highly combustible.
Hydrogen sulfide is not odorless.
Not really.....
Hydrogen is released while charging.
The covalent compound HCN is called hydrogen cyanide.
Scott C Steinsberger has written: 'Laboratory and field evaluation of methodology for determination of hydrogen chloride emissions from municipal and hazardous waste incinerators' -- subject(s): Environmental aspects, Environmental aspects of Hydrogen chloride, Hazardous wastes, Hydrogen chloride, Incineration
Hydrogen gas is lighter than air, so it will rise and float if released. However, it is also highly flammable and can be hazardous, so caution should be taken when working with hydrogen.
Methane and Oxygen
If consumed rubidium may be poisonous, but other wise it isn't.
Hydrogen bromide is typically purchased in compressed gas cylinders from specialty gas suppliers. However, due to its hazardous nature and regulatory restrictions, it may not be readily available for purchase by the general public. It is important to follow proper safety protocols and regulations when handling hydrogen bromide.
Some hazardous chemicals can be made non-hazardous and some cannot.
Dangerous in what way? hydrogen just being burned does not contribute to global warming, but what about 'making' the hydrogen? Does that use other fuels that contribute to global warming? Hydrogen is more explosive if that is what you mean by dangerous. Hydrocarbons burn to form carbon dioxide which contributes to global warming.