Fishing Oxygen Systems Rules of the Oxygen Road

WEBPAGE UPDATED            Tuesday  June 22, 2022


Special fire safety rules do apply for “Oxygen-enriched” and “Oxygen-rich” areas inside all boat livewells and bait tank gas space environments that contain 24% – 100% oxygen. Ambient air contains < 21% oxygen/79% Nitrogen gas. These rules also apply should oxygen gas accidently escaping into boat lockers, boat bilges, battery boxes or all boat compartment, wiring chases on a boat. These special rules do not apply to ambient air environments that ARE NOT OXYGEN-ENRICHED OR OXYGEN-RICH.

FACT: Ambient air (all mechanical aeration livewell equipment), all livewell air vents including the popular V-2T air vents, air pumps, air blowers, air bubblers or water pumps WILL NOT, CAN NOT enrich livewells with oxygen gas. Air contains slightly less than 21% oxygen gas. Period. Additional supplemental oxygen >24% purity is necessary to create an oxygen-enrichment and oxygen-rich environments in livewells, bait tanks boat bilges, lockers and compartments containing live electricity.

All mechanical aeration devices and livewell pumps that entrain ambient air via venture device or water pumps that have air leaks on the inlet side of the water pump can supersaturate livewell water with Nitrogen can supersaturate the water and fish’s blood with Nitrogen gas causing Pop-Eye and gas embolism. Nitrogen gas supersaturation is a serious condition that can also affect SCUBA divers breathing air at depth… it’s called the Bends.

“OXYGEN-ENRICHMENT” / “OXYGEN-RICH” advertisement sounds impressive to fishermen, but when you see these words used to advertise fishing oxygen systems, oxygen generators, livewell air vents, etc., what do these 2 words really mean?

Air Products  – “The hazards of oxygen and oxygen enriched environments”

Oxygen-Enriched Classification – OXYGEN GAS FIRE SAFETY


“OXYGEN-ENRICHED” and “OXYGEN-RICH” mixtures or atmospheres is defined as any environments containing 24% to 100% oxygen by volume.  The reactivity of oxygen significantly increases the risk of IGNITION and FIRE in oxygen enriched atmospheres.


Fact: The difference between the O2 concentration in ambient air and an Oxygen-Enriched or Oxygen-Rich environment is only 3.2.% oxygen concentration.

Materials that may not burn in normal air environments may burn vigorously in an oxygen-rich environment. Sparks normally considered as harmless may cause fires. All materials that burn in air including metals under water may burn with a hotter flame and propagate at much greater speed.

FACT: Cotton clothing, fish rags, etc. absorb oxygen like a sponge absorbs water and oxygen is heavier than air. Oxygen leaking into the boat’s bilge settles in the lowest part of the bilge. Spilled fuel oil, batteries, live electricity, fuel often accumulated in the bilge area.

Oxygen-enriched or oxygen-rich boat livewells and bait tank environments present special fire safety issues that do not apply to livewells and bait tanks aerated with ambient air (mechanical aeration, electrical bilge pumps, livewell and bait tank water pumps. Air contains <21% oxygen gas at sea level and mountain elevations.

Any and all supplemental oxygen devices fishermen use in boat livewells and bait tanks that will cause oxygen enrichment (24% oxygen or oxygen supersaturation) require special Fire Safety precautions and rules.

FACT: The Oxygen Rules of the Road do not apply to aerated boat livewells and bait tanks that are mechanically aerated with ambient air, air pumps, water pumps, etc.

FACT: The “Oxygen Rules of the Road” applies to all livewell/bait tank oxygenating devices, products and equipment that advertise “oxygen-rich” or “oxygen-enrichment.”

Knowing, understanding and practicing Oxygen gas safety rules with all oxygen-enriched livewells and bait tanks is vitally important!

Knowing how to identify livewell equipment that will cause oxygen-enrichment is a serious safety matter.

*The product advertisement and product literature ADVISO will state if the product will create an “oxygen-rich” or “oxygen-enriched” livewell environment.



If you DON’T KNOW, understand or practice fire/explosion safety or you don’t know the Rules of the Oxygen Road: DO NOT INSTALL OR USE ANY LIVEWELL OXYGEN GAS OR HIGH-PRESSURE OXYGEN CYLINDERS SYSTEM ON YOUR BOAT. FIRE/EXPLOSION HAZARD

Contact an oxygen expert that knows how to safely install an oxygen system on your boat. An expert can and will teach you how to store, handle and use pure oxygen and oxygen equipment safely.

FACT: Oxygen is not air. Never treat these 2 different gases the same.

Here’s a few “Rules of the Oxygen Road” regarding oxygen gas and high-pressure oxygen cylinders.

Never use, contaminate or lubricate oxygen equipment with petroleum base products, oil, grease, WD-40, Salt Away, etc. EXTREME FIRE HAZARD

Never look into your live well with a burning cigarette in your mouth. EXTREME FIRE HAZARD

Always secure high-pressure oxygen cylinders to the hull of your boat with strong secure straps or brackets. Never leave a high-pressure oxygen cylinder free standing vertically at any time. If your O2 cylinder is not safely secured, lay the cylinder down horizontally. SAFETY HAZARD

Never secure or transport high-pressure oxygen cylinders to then plastic ice chest lids, in the boat’s bilge or battery box or anywhere that oil or gasoline can contaminate the equipment. Never secure or transport oxygen cylinders anywhere electricity can arch on any metal components of an oxygen system or burn oxygen tubing. FIRE HAZARD

Steel oxygen cylinders require hydrostatic testing every 10 years; aluminum oxygen cylinders every 5 years. The last hydrostatic test date is stamped into the metal on the cylinder’s shoulder. The stamp will be the month (a triangle, diamond or star) and the year tested… 03 ∆ 14. HIGH PRESSURE OXYGEN CYLINDER SAFETY, EXPLOSION HAZARD.

Always use a clean rag with freshwater to clean oxygen system components. Never submerge oxygen regulators or high-pressure oxygen cylinders under water. If you need more than water for cleaning, use ethanol (EVERCLEAR), it’s oil free (rubbing alcohol contains trace amounts of oil). Use ethanol externally on system components only and allow to dry completely after cleaning. Do not use ethanol internally anywhere within the gas circuit. Use equipment only after all ethanol has completely evaporated. Never expose ethanol vapors or ethanol to oxygen (the gas). Methanol should never be used to clean oxygen  equipment, methanol is not oil free. OIL CONTAMINATION IS A FIRE HAZARD

Always crack (open the oxygen tank valve slowly to blow out dust and foreign material) in the oxygen cylinder valve before connecting the regulator. After connecting the regulator, open the oxygen cylinder valve slowly. HIGH PRESSURE SAFETY

Always use system components including oxygen supply tubing that has been CLEANED AND CERTIFIED FOR PURE OXYGEN SERVICE. Never use air tubing purchased at hardware stores or aquarium stores for pure oxygen service @ 50 PSI. Air tubing contains trace amounts of petroleum product (oil). FIRE HAZARD

Never use cleaning solvents, WD-40, isopropyl alcohol (household rubbing alcohol) or any other cleaning products or any oil base products on oxygen equipment or in oxygen enriched environments. FIRE HAZARD

Never use oil or oil-based lubricants on oxygen regulator threads or cylinder valve threads, hose barbs etc. If you must use lubricants, special lubricants compatible with pure oxygen service must be used. FIRE HAZARD

Never place oxygen supply tubes adjacent to live electrical wires or inside a wiring chase, battery compartment or boat bilge area.  FIRE HAZARD


FACT: A boat fire extinguisher will not extinguish an “oxygen-rich” and “oxygen-enriched” environments. FACT: Extinguishing an Oxygen-Rich Fire – First turn off the Oxygen cylinder valve the oxygen gas source terminating the oxygen flow or oxygen production with TH Marine Oxygenator™, PSA oxygen generators and then put the fire out with your boat fire extinguisher.

FACT: If any livewell oxygen system does not deliver enough oxygen for enrichment (24% – 100% oxygen) the fire hazard is no greater than the fire hazard in air. Livewell oxygen systems (oxygen injection systems and oxygen generator systems) all claim to deliver high concentrations of oxygen resulting in oxygen- enrichment and oxygen-rich livewell environments.

These oxygen safety rules and more apply to all livewell oxygen systems and all oxygenated livewells and bait tanks on boats or on land.

Livewell oxygen equipment that cannot deliver or generate enough oxygen to produce oxygen-enrichment, provide 24% O2, are no more effective than an aerator pumping air or livewell water pump pumping water through livewells and bait tanks. Actually, they can suffocate bait or fish in bait tanks and livewells quicker than aerators and water pumps when and if they fail to provide the minimal safe DO Saturation during summer transports.

A PARADOX: Oxygenator™ and FishO2™ salesmen and boat dealers that sell these livewell oxygen generators when asked, do not and will not mention or discuss oxygen gas (fire) safety on boats yet their salesmen and promotional literature says their livewell equipment generates 90% and 100% pure oxygen. CAUTION: A HIDDEN FIRE HAZARD



Oxygen – rich environments (24% oxygen or >) accumulates in livewell gas spaces when the livewell lid is closed.

Oxygen-rich environments requires the same safety precautions and fire safety standards as pure 100% gaseous oxygen environments. Know oxygen fire risk on sport fishing boats and practice oxygen fire safety. promotional advertisement

• Creates an oxygen-rich environment to keep fish fresh and lively

“This is the most efficient means of maintaining high-levels of oxygen in a livewell and nothing comes close to the OXYGENATOR’S ability to create an oxygen-rich environment.”

Although fire safety is a non-issue in this advertisement, all oxygen–rich gas spaces demand special respect in any livewell. Oxygen is not Air.


TPWD, Inland Fisheries Division, San Antonio, TX Publication by Fishery Biologist Randy Myers AquaInnovations Oxygenator 2-14-2012

Claims to “generated 100% pure oxygen.”

Oxygen fires are very different than ambient air fires. It makes no difference if the oxygen comes from a PSA oxygen generator, electrolysis oxygen generator, liquid (LOX) or compressed gas oxygen cylinder.

FACT: The oxygen source must be terminated before the fire can be extinguished with a standard boat fire extinguisher.

Not knowing and not understanding the gas or your livewell oxygen equipment increase fire risk on your boat. Knowing oxygen safety and oxygen rules are the issue.

Practicing the “Rules of the Oxygen Road” are necessary to reduce risk and maximize safety. Think safety and be safe when using oxygen and any kind of livewell oxygen system. Oxygen and oxygen equipment demand utmost respect.


When buying a high-pressure oxygen regulator for your live well oxygen system, always confirm with the seller that the regulator you’re buying has passed the Compressed Gas Association (CGA) E-4 Ignition Test and is Certified.

The Oxygen Edge™ regulators and “Generic Oxygen Regulators” are E-4 Tested and Certified, safe from ignition or fire caused by adiabatic compression. OE regulators are back pressure compensated in order to deliver a continuous precision dose of oxygen. OE regulators provide the correct dose of oxygen for live bait and fish loads ranging from several ounces to 225 lbs.

Safety on fishing boats is a matter of your peace of mind when fishing oxygen regulators are exposed to extreme saltwater environments. Many brands of oxygen regulators sold to fishermen for livewell oxygen systems have not passed the E-4 Ignition Test and are not Certified. Caution is advised if the regulator is not E-4 Ignition Test Certified.

The Compressed Gas Association (CGA) recommends E-4 Ignition Testing for all manufacturers of click style high-pressure oxygen regulators.

Be informed and always confirm with the seller about E-4 Testing and Certification before you purchase any oxygen regulator.