| WARNING Take extreme caution when handling the inflated balloon. Read the Safety Instructions for Balloon Operators before you start preparing the balloon. |
| WARNING Normally the balloon-lifting gas (hydrogen or helium) is supplied in gas bottles, but hydrogen can also be produced with a hydrogen generator. Carefully study the operation and safety instructions for the gas bottle facilities or the hydrogen generator. |
| WARNING Vaisala recommends preparing the balloon in a balloon-filling shed. The balloon-filling shed must be well ventilated so that possible gas leaks do not remain inside the shed, even in situations when there is no electricity. |