You're a certified diver. You check your cylinder to ensure it’s above 200 bar, inflate your BCD, and take a breath from your second stage. You have your own gear, serviced annually by a certified technician or dealership. Or maybe you're on a course, using the dive store's equipment, which they assure you is well-maintained.
After a briefing and careful planning, we're ready to dive.
But wait—what am I breathing? It’s air, right? 21% oxygen. Or maybe, if I’m trained and certified, it’s nitrox—enriched air with up to 40% oxygen content. That all sounds good. But how was this cylinder—likely made of aluminum—filled? It was pressurized with a high-pressure, oil-filled rotating pump, taking it from 1 bar at the earth’s surface to the 200 bar I see on my gauge. To put that into perspective, what’s the pressure in my tires? Maybe 36 PSI? That’s only about 2.5 bar—nowhere near the 200 bar in my cylinder!
In cities, air quality is compromised by car emissions, dust, and pollution. People also exhale carbon dioxide. The compressor filling my breathing gas cylinder is full of oil. With some knowledge of mechanical systems, it’s reasonable to assume that my breathing gas could be contaminated. We’re dealing with pollutants (VOCs), car emissions (CO), exhaled air (CO2), and compressor oil—all potentially ending up in the gas cylinder I rely on to breathe underwater. And then there’s moisture, which in breathing gas can carry contaminants due to condensation.
How can I breathe that?! Well, we filter the gas at high pressures to reduce these contaminants to safe levels for human consumption. The global standards are Grade E or EN12021. For the tech-savvy: 5 ppm CO, 1000 ppm CO2, 0.34 mg/m³ oil, and H2O less than 5°C below the lowest ambient temperature. The filter removes water, converts CO into CO2, and then removes oil, VOCs, and some CO2. Sounds good, right?
Yes! It’s generally safe, and millions of dives occur safely every year. But the filter change schedule is crucial. If someone tells you to "smell the gas to check," they don’t understand how breathing gas is created.
1. What does CO smell like? (Hint: You can’t smell it.)
2. If you can "smell" any bad taste or odor, the gas is already more than 50 times over the limit classified as poisonous to humans... oh dear.
The only way to know for sure what you’re breathing (as is required in the airline industry, hospitals, etc.) is to test every cylinder you plan to use. Test for what? At the very least, CO—but ideally, test for everything. Every dive operation should guarantee clean gas—after all, you’re paying for a full cylinder to dive with. I don’t think anyone wants high-pressure poisonous gas, right? Would you want that for yourself or your family?
Clean gas is essential, and it’s not just about safety. Bad gas can damage your lungs, your regulator, the BCD’s inflation bladder, your pressure gauge, and your low-pressure hoses. In the end, it not only affects your health but also costs you more in gear maintenance due to hydrocarbons in your equipment. You must demand clean breathing gas.
But how clean is clean, you might ask? Is just washing your gear enough? Are we truly washing our gear correctly? Have you read the manual for your gear and checked the wash and care instructions? When renting gear, are your hygienic standards being met? These are tough questions with difficult answers. In reality, it’s not easy for every shop to show you the exact condition of their rental gear, even if they’ve kept it in top condition.
But do their standards meet yours? Have things been accumulating and neglected over time? The answers to these questions are yours to determine. Your level of comfort with your decisions is, at the end of the day, yours alone.
As professionals in the industry, we can provide you with the reality and the education. But ultimately, the choice is yours—whether to invest in your own gear or not. The benefits of ownership are varied, as we’ve discussed in a previous blog.
Some dive operations have constant monitoring devices that shut down the system if they detect unsafe contamination levels. Many OEMs offer these, but one of the most trusted is the SECURUS system from Bauer.
This system provides peace of mind to divers and professional dive teams across various fields, including defense, commercial diving, research, rescue, public safety, and recreational training centers.
Keep your equipment in top condition by servicing it annually or every 100 dives, washing it correctly, and only using clean gas. Investing in the best quality gear for your safety also generally offers the best return on investment. We prefer SCUBAPRO for its decades-long track record of providing security to divers, with excellent global and local support, plus a full range of products to suit any diving you do now or plan to do in the future.
Clean gas and bubble-free gear are our standards. Reach out to us for more information or to get recommendations for the best dive shops or trainers anywhere in the world. If we don’t know, we’ll find out.
Kommentare