Helium or air? A buyer's guide to filling foil balloons
Every foil balloon order eventually produces the same support email: the customer filled it and it will not float. Usually the answer is the gas, or the amount.
Helium: the only gas for floating
Helium is inert, safe and the standard for retail balloons in the EU, UK and US. It is also expensive and increasingly supply-constrained, which is why balloon size and fill level matter commercially: a half-filled 18-inch balloon floats badly and wastes gas.
Air: fine for hanging, not for floating
Air-filled foil balloons are heavier than the displaced air only when filled with helium — with air they will not rise at all. Air is correct for garlands, arches, table decorations and anything supported by a frame or tape. Air-filled balloons also last weeks instead of days, which is why garland kits are sold as air-fill products.
Never hydrogen
Hydrogen is cheaper and lifts slightly better, and it is banned for consumer balloons in most markets for a reason. If your packaging does not say which gas to use, add it — "Fill with helium or air. Never use hydrogen." This one line protects you in a liability claim and costs nothing to print.
Fill level: the specification nobody writes down
Filling "until it looks full" is how batches fail. Specify a percentage — 90% for retail 18-inch balloons is standard — and put a size reference on the packaging if you can. Under-filled balloons disappoint; over-filled ones split at the seam.
What to put on the pack
- Gas: helium or air, never hydrogen
- Fill level and expected float time
- Size when inflated
- Not suitable for children under 36 months (uninflated balloons are a choking hazard)
None of this is decoration. In the EU, missing warning text is a compliance problem, not a marketing one.