Air contamination - Oil

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

no its not veg oil that I am aware of , there is a rix compressor that doesn't use any oil at all but they have a very limited life span compared to an oil based compressor so most lds don't have them
 
I think RIX would be surprised to hear that their compressors have a very limited lifespan. A shorter service interval yes, but they are well built and can last a long time.
 
why because you own one , YES compared to an oil based compressors they WEAR OUT faster,(read compared to ) 40 years in the industry has shown me that . plus physics so after you run yours for 10 years come talk to me what its cost to run ....
 

This is an older video but this is what happens when synthetic oil as used in compressors overheats or bypases filters. You get toluene gas.
 
YES compared to an oil based compressors they WEAR OUT faster

How is that..........Exactly ?

40 years in the industry has shown me that

Doing what for the last 40 years ............Exactly ?

plus physics

Now I would be very interested for your physics, for background you understand and for you to explain this part with a little more precise detail. Thanks.
 
Hi, hope someone can help with my questions.

Yesterday I did two shallow dives (I am a new diver), but during the second dive noticed that the air had a bit of a taste. Once finished I smelt the air and it definately had a rubbery smell. I have been told it is likely oil contamination in the air.

Last night the back of my throat has a burning feeling, and now also my chest feels quite irritated and a burning feeling.

Has anyone else experienced these oil contamination symptoms? Now it feels like when I have a chest cold, and irritated, burning . Will the symptoms resolve themself, or have I done permanent damage? I am a bit worried about it.

Thanks for your help!


As a new diver you need to be very careful in how you get through the learning phase into experience. Each route is different, yours was unfortunate but at least the term tragic was avoided.

Your first tank fill of the day was I assume fine, yet the second tank fill was contaminated, how this happened I will explain later if you like but you now have a direct understanding of the importance of purity when breathing compressed gas underwater and the consequences when not.

Sadly your dive supplier who supplied you with that fill clearly does not have the same regard to your health and safety and was in effect trying to kill you.

This is rule number 1.

Keep that thought in you mind for each and every scuba shop you use for a fill from now on regardless of the bravado and bull they trot out. Regardless of how long you remain a diver.

They will kill you by ignorance, they will kill you by farmyard stupidity, they will kill you by using you as an easy cash cow with which to make a few dollars.
They will ignore the safety requirements, use antiquated equipment, self service the components skimp on the replacement and service schedules and with scant regard for any responsibility for your safety.

The compounds you breathe from these oil lubricated compressors are complex and potentially dangerous, the levels of these compounds is normally controlled by use of a filter to adsorb these contaminants.
But in the right circumstances these accumulated adsorbed complex chemicals can just as easy be desorbed back out and into you tank.

In addition all it takes is a small compressor overheat for the oil breakdown to increase and the filter is overwhelmed resulting in you breathing a range of compounds from carcinogen to irritant the degree to which you were exposed will effect the damage caused. There are three other causes that have the same effect all caused by the use of oil inside a compressor they expect you to breathe from.

Further the chemical filter by it’s very nature will fail, the oil lubricated compressor likewise over time will fail as does the very oil in it with which to lubricate the running gear.
When any of these three components over time fail you are at risk. Take good care to evaluate the dive shop, the state age and condition of the compressor if you can although most hide the junk out back so you can’t see it.
Look for an air purity certificate on the wall located at the point of dispensing, make sure it is in date.

Now also the filter by it’s nature will fail, the oil lubricated compressor likewise over time will fail and the oil used will breakdown. Test you air purity before you dive it, there are various testers available. Look up divers CO testing analysers would be my first go buy after this wake up call.

By contrast an oil free compressor dismissed surprisingly by others here, cannot do this ever, even without filtration it is still clean pure air, you can even drink the contents of the condensate drain as it is pure distilled water.

Ignorance is not the main reason oil free compressors are not popular in scuba dive shops, nor is the ease of service, or the life expectancy, or the purity of the gas they compress. Sadly you as a customer are classed as a punter and your life expectancy and long term health is not even a consideration with these folk its all about making most money out of you for silly courses with the least outlay.

Just remember rule 1.

You now have had your first experience of what that is like at the recieving end as a diver and survived. Learn by it. Iain
 
One thing I should crittically add is the importance of your nose.
It is not only the nearest thing to the sun when on the beach,

As a diver it is a complex and sensitive tool by which you can smell problems before you commit to breathing them.

If you forget ignor disregard object dissagree or laugh off all I have said remember one thing

Next time and for each and every time after every fill you smell your air, in the shop before you take it away and again before you clamp it up with the DV before the dive.

If its acrid smoky or oily smelling regect the fill and dont dive.

Conversly if its oil your concered about, an oily smell but not acrid. Another small "trick" is to stuff a white clean cotton rag into the cylinder HP valve hole and bleed 10 seconds of air content then carefully look for discolouration, if its oil you will see it, dont breathe it I guess.

However shallow. Iain
 
Last edited:
No, dive compressors do not use vegetable oil, although I have read of some people using it, totally against all recommendations. As a compressor owner, I would recommend only using synthetic oil for reasons I will not go into here.

Many times I have not been able to taste the oil in a bad tank on the surface, it only became apparent at depth. In some cases, it seemed fine till 30 m or so. My guess is that it was a small percent but the depth made it worse due to the fact I was breathing 4 times the air as I was when I left the surface.
 
The problem is often that small amounts of oil usually mean there are other contaminants, too - and these problems get amplified at depth. Not only can these contaminants cause lung damage, it is also possible that these oily compounds can exhibit a highly narcotic/anesthetic effect. This can cause severe impairment of decision making while underwater or even unconsciousness. Lamar English wrote an amazing account of his experience with bad air fills while on a rebreather that caused some long term problems...I wish I could find the article, because like everything else he wrote, it was fantastic.

Anyway, your description of the "rubbery" smell made me immediately think of toluene - which is really bad stuff! I am very glad that you are feeling better and that there was no apparent serious outcome here. I would like to point out, though, that this is a really good reason to pick up a CO detector. Like I said, bad gas usually has more than one contaminant, and CO breakthrough is commonly associated with the presence of other stuff. And fortunately, if there is breakthrough happening in a filter system, CO is typically elevated. Thinking about incidents like this finally got me to pick up a CO detector myself this year.

Edit: Here's the post from Lamar - Cave Diver's Forum
 
Last edited:
Are you suggesting that the compressor oil was diluted with toluene? Because I can't see toluene becomes a chemical/physical by-product in such situation.
 
https://www.shearwater.com/products/perdix-ai/

Back
Top Bottom