FAROE DIVE | Is it time to reconsider hydrogen-oxygen mixtures in commercial diving?

Eva Andrésen
2 days ago
2 min read

An older gas mixture is gaining renewed interest: hydrogen-oxygen, or hydrox.

Is it time to reconsider hydrogen-oxygen mixtures in commercial diving?

As the professional diving industry moves deeper and further, we are constantly looking for new ways to increase working depth, safety and efficiency. Helium-oxygen (heliox) is still the standard in deep and saturation diving, but an older gas mixture is gaining renewed interest: hydrogen-oxygen, or hydrox.

Why now? Because technological advances and new research are making hydrox both more realistic – and potentially beneficial.

Why is hydrogen interesting?

Low breathing resistance: Hydrogen is much less dense than helium or nitrogen, reducing the strain of breathing at great depths.

Better thermal properties: Hydrogen does not conduct heat away from the body to the same extent as helium – an advantage for long dives in cold water.

Price and availability: Helium is expensive and in limited supply. Hydrogen is cheaper, more readily available and can be scaled up.

Safety – still a concern?

Yes – but it can be managed. Hydrogen is flammable, but with low oxygen concentrations (typically below 4%) and proper gas management, the risk remains at an acceptable level. Programs such as COMEX’s HYDRA dives in the 1980s have already proven that it can be done.

Modern gas management systems and chamber controls have improved significantly, significantly increasing safety.

What does the latest research say?

New trials – particularly in Europe and China – are showing promising results. Hydrogen appears to counteract HPNS (High Pressure Nervous Syndrome), which often limits deep heliox dives. It also has a rapid diffusion into tissues, which can reduce decompression time and stress. Hydrox will not replace heliox everywhere, but for deep diving it could become a valuable tool.

What does the future hold?

Hydrogen-oxygen mixtures are no longer just theory – they are making a comeback as a serious option. If you work in dive operations, engineering or training, it may be time to look at hydrox again.

The future of deep diving in commercial diving may well be based on the lightest molecule in the universe.