Breathing Gas Quality Assurance

Assuring safe gas quality and establishing what to do in the event of contamination (or suspected contamination) are essential actions that must be considered by all who operate gas filling stations.

Whether you fill cylinders for your own business or others — or have cylinders filled for your clients — it is important to take note of the quality assurance measures in this article. No matter how or where your cylinders are filled, you are responsible for providing your clients with safe breathing gas.

Download DAN’s HIRA Guide, Free of Charge

Before you begin your assessment of your operation, download the DAN Hazard Identification and Risk Assessment Guide (HIRA). This comprehensive guide provides information on many of the often unique and unexpected risks in a dive operation. DAN is pleased to offer the digital edition of this guide to all dive businesses at no cost. It includes several references to gas safety regulations in our industry. The air quality table in the HIRA guide is based on real risks.

How Often Should I Have My Air Quality Tested?

Testing frequency is not really established by U.S. regulations. However, some dive certification agencies and other countries do provide requirements.

We should keep in mind that any air quality test is taken on a day and at a time; this does not provide assurance that a few minutes, days or months later, the air does not become contaminated.

A test is thus only one step in a list of important actions to consider in assuring clean gas. How often you test therefore depends on an assessment of applicable contamination hazards near your facility.

Do the Contaminant Limits Actually Mean Something?

In most cases we rely on safety, research and regulatory organizations to determine acceptable contamination limits. Not much work has been done on breathing gases for scuba diving when it comes to contaminants such as CO, CO2 and particulates. DAN has taken this one step further and assessed these limits in terms of the three primary hazards that they may present to the scuba diver: fire, mechanical and physiological.

What Should I Be Doing?

There are certain preventative steps dive operators can be taking to ensure quality breathing gas. Proper compressor maintenance, monitoring filter effectiveness, controlling the air intake location, inspecting cylinders and clean handling during cylinder maintenance are some of the actions you can take.

Monitoring your actual air quality test reports to see whether there are any patterns in rising contaminant levels, or instances in which the limits were approached will provide additional early warnings. The atmospheric value of CO2 today is around 420 ppm. Depending on your recent test results this may lead you to ask yourself: “Why is my result higher than this, even if it meets the specification?” This could help you in tracing what has changed — such as a new compressor intake position or a restaurant that has opened up next door with an extractor fan close by.

Good record keeping of all your actions to ensure clean gas will not only provide you with better assurance of control, but also provide better validation if something were to happen and you were held accountable in some way.

What to Do in the Case of Contamination

Sometimes accidents happen despite our best efforts to prevent them, and sometimes they happen because of lack of discipline or even negligence. In the moment it doesn’t really matter what the cause was; it is essential to know how to react once you find out (or even suspect) that gas may be contaminated.

You need an effective and appropriate emergency plan that details who to notify, what steps to take to assist any injured diver, how to prevent further contamination injuries and how to prepare for any subsequent investigations or actions.

Never attempt to hide any of your actions — doing so could result in repeated incidents or worse yet, jeopardize your position with respect to any subsequent legal actions.