Administering oxygen — am I allowed to do that?

Am I allowed to do that—and can I do something wrong?

We give oxygen when we think someone might need it—even if we’re not completely sure. Still, the same questions come up in every course: Am I even allowed to do that? Am I going to make things worse? Am I liable if …? What if they sue us?

The short answer: This is an emergency. You’re providing first aid and doing what you can to help. And in Europe, the law is on your side almost everywhere.

Forget the card. Help.

Someone has symptoms after a dive, oxygen is available—and now someone is asking for your O2 provider brevet?

Don’t let help fail because of that question. A missing or expired card is not a medical reason to withhold oxygen. If you can operate the system that’s there, help and arrange further care.

If you’re unsure how to use it, get support: from someone on site, from the device instructions, or when you call emergency services. Get the kit, prepare to administer oxygen, and stay with the person. You don’t have to wait doing nothing until someone shows up with the right proof.

That’s exactly why we practise using the oxygen kit: so in an emergency the steps are second nature and no one wastes time wondering whether their brevet is still valid.

Europe: Helping is mandatory—and helpers are protected

The laws differ in the details, but in almost all countries in continental Europe the same two principles apply:

Anyone who fails to help in an emergency commits an offence—provided help is necessary and reasonable, i.e., possible without significant danger to themselves. At a minimum, helping means: calling the emergency services and getting help.
Anyone who helps in an emergency using an appropriate means is not acting unlawfully—even if they do something that would otherwise not be permitted, and even if it later turns out it wasn’t that serious (the “necessity defence”).

Country	Duty to help	Protection for helpers
Germany	§ 323c StGB — Failure to render assistance	§ 34 StGB — Necessity defence
Austria	§ 95 StGB — Failure to render assistance	Necessity defence (“extra-statutory”)Recognized by case law
Switzerland	Art. 128 StGB — Failure to render emergency assistance	Art. 17 StGB — Necessity defence
France	Art. 223-6 Code pénal — non-assistance à personne en dangerFailure to assist a person in danger	Art. 122-7 Code pénal — état de nécessitéNecessity defence
Spain	Art. 195 Código Penal — omisión del deber de socorroFailure to render assistance	Art. 20.5 Código Penal — estado de necesidadNecessity defence
Italy	Art. 593 Codice penale — omissione di soccorsoFailure to render assistance	Art. 54 Codice penale — stato di necessitàNecessity defence
Netherlands	Art. 450 Wetboek van Strafrecht — nalaten hulpverlening bij levensgevaarFailure to render assistance in immediate danger to life	Art. 40 Wetboek van Strafrecht — overmacht (noodtoestand)Necessity as a ground of justification

Quick overview. The necessity rules mentioned apply only if their legal requirements are met; they do not provide blanket liability protection. In the Netherlands, criminal liability under Art. 450 in particular requires that the person in need dies.

You don’t have to be a perfect helper

First aid happens under uncertainty. You don’t yet know exactly what happened, you don’t have a full diagnosis, and you still have to act.

For Germany, the German Social Accident Insurance (DGUV) explicitly clarifies: lack of knowledge and lack of first-aid practice generally cannot be held against helpers as gross negligence. So a mistake while helping does not automatically mean you’re liable for it.

The legal details vary from country to country. There is no worldwide liability guarantee. But fear of not doing it perfectly should not stop you from providing necessary help.

For our course, that means: understand oxygen administration, get to know the kit, and help in an emergency. We’ll sort out the brevet question before or after.

The exception in Europe: the UK and Ireland

In English and Irish law there is no general duty to help strangers. But anyone who helps is protected there too: In England and Wales, courts must take into account that someone intervened in an emergency (Social Action, Responsibility and Heroism Act 2015); Ireland has its own law protecting helpers (“Good Samaritans”).

And outside Europe?

USA: In most states there is no general duty to help (exceptions include Vermont, Minnesota, and Rhode Island). However, all states have “Good Samaritan” laws: Anyone who helps in good faith is not liable—except in cases of gross negligence.
Canada: Quebec’s Charter of Human Rights obliges everyone to help a person in mortal danger; the other provinces protect helpers with Good Samaritan laws.
Australia tends to follow the English model with Good Samaritan laws; many countries in Latin America tend to follow the Spanish model, where failure to render assistance is a criminal offence.

So the pattern is the same everywhere: There are countries where you must help, and countries where you may help and are protected when you do. There are practically no countries where well-intentioned first aid with appropriate means is punished.

As a dive pro: even more responsibility

Everything above applies to anyone who just happens to be there. If you’re out with guests or students as a guide, divemaster, or instructor, you have more responsibility—and in virtually all legal systems, including the UK and the USA: You have a duty of care toward the people you’re responsible for. If you don’t help, you may be liable not only for failing to help, but for the consequences themselves. So for professionals, all the more so: carry oxygen and use it.

Brief overview, not legal advice. As of: October 2026.

Can you do something wrong?

In theory: Is there anything we could be so wrong about that oxygen becomes dangerous? Three questions come up again and again.

Medical or industrial oxygen?

Purity: both 99.5%.
Difference: expiry date and paperwork. Medical oxygen is considered a medication, needs an expiry date, and must be replaced regularly. But nothing happens to the oxygen itself in the cylinder.
In practice it doesn’t matter—and for first aid it doesn’t matter legally either—use what you have!

Why 99.5%? A large storage cylinder is emptied before filling—but “empty” means 1 bar, not a vacuum. If it’s then filled to 200 bar, half a percent remains where you can’t be 100% sure what it is. Probably oxygen, maybe a bit of air. No problem. And if you filled your Deco stage with welding oxygen, you can of course give it to someone with a diving accident. After decanting, nobody can tell which oxygen it was anyway—it’s just oxygen.

When does it become too much? Oxygen toxicity

Oxygen can become toxic—that’s true. There are two types:

CNS toxicity (seizures): It matters underwater or during hyperbaric treatment, i.e., at increased pressure. On land we breathe at 1 bar—so the pressure is simply not high enough.
Pulmonary toxicity (lung function declines): It can become relevant even at 1 bar, but only after very prolonged breathing—after many hours.

What we do in first aid—twenty minutes, half an hour, an hour of oxygen until handover to EMS—is nowhere near that. Most of the time we don’t even have that much oxygen with us. If someone needs oxygen for longer, they belong in a hospital or a hyperbaric chamber anyway, and you coordinate that with a dive physician, for example via the hotline.

The one exception: panic and hyperventilation

There is exactly one situation in diving where oxygen doesn’t help: a panic attack with hyperventilation. Panic attacks are relatively common and can be triggered by critical situations while diving—for example, if someone thinks they ascended too fast.

Anyone who is hyperventilating breathes off too much CO₂. That sends false signals to the brain and causes symptoms that are easy to confuse with a diving accident: tingling in the hands, shortness of breath, dizziness.
There’s enough oxygen. What the body needs right now is CO₂—so calmer, slower breathing.
Help the person calm down: talk to them calmly, stay with them, and breathe slowly together with them.

Panic can cause symptoms—but it can also be the reaction to a real diving accident. Both can happen at the same time. So “they’re just scared” is not an all-clear.

If a diving accident is a possible cause, don’t delay giving oxygen just because you don’t have a definite diagnosis yet. Stay with the person and get medical support.