Like methane and propane, hydrogen is stored in compressed form in cylinders. If the most common safety rules are observed, such storage does not pose a threat. It stands to reason why gas cylinders can be purchased in retail.
As we know from the school course of physics, an explosive concentration of hydrogen is achieved only at 4% content of this gas in the total volume of the mixture. Moreover, a spark/source of ignition is required for inflammation or explosion. Hydrogen is a volatile gas (unlike propane, it does not accumulate), so it is extremely difficult to reach a critical concentration. For example, a 10 liter cylinder contains 3.5 m³ of hydrogen. If we imagine that in a two-room apartment with an area of 60 m² and a ceiling height of 3 m (volume 180 m³) all the hydrogen is let out from the cylinder and assume that the room is 100% airtight (hydrogen remains in the room), its concentration will be less than 2%. No ignition/explosion will occur.
In the open air, like a field or forest, it is not possible to achieve even 2% hydrogen concentration.