Gassy karting suit!

No, it's not the gassy problem you might be thinking of.  My sons have ben racing in an "arrive & drive" karting series this summer and while racing one night this week my youngest son got a fair bit of gas on his suit.  I suspect the gas cap wasn't on properly and it soaked the shoulder and side of his suit, his t-shirt and of course him.  While he seems to smell better now his suit is really holding onto the smell.  We've washed it in the washing machine and had it outside for a couple of days.  It's a little better but definitely not great.  Anyone have suggestion on how to remove a gas smell from the suit?

Thanks!

Best thing is time, open air, and sunshine. 
 

problem is fuel is a light hydrocarbon that is chemically similar to some of the polymers in the synthetic fibers of the suit. It works its way into the fiber and is really hard to get out. 
 

if you want to try cleaning it again read the suit manufacturers recommendation. Some fireproof suits have very specific washing methods or you can decrease the flame resistance.  Something like Dawn liquid or even a degreaser will work better but don't run those in a washing machine. If you try degreaser make sure it's a more neutral pH instead of heal high pH like purple stuff or Awesome. 

I bought one of those cheap Mexican hoodies when I was in college and I'm pretty sure it was made from kerosene soaked rags. 
 

I washed it a bunch of times without success, and then my sister suggested Ivory Snow, because it's soap and not detergent, or something like that. 
 

it worked. 
 

Thanks very much!  Thankfully this is just a karting suit rather than a racing suit so I don't have to worry about the fireproofing aspect.  I'll scrub it by hand with Ivory/Dawn, spray it out again and hang it in the yard for a few days.

Much appreciated!

Tincture of time. 

I wonder if a soak in ammonia would help.  From what I remember of my limited chemistry, and Dad's more advanced chemistry, ammonia reacts with oils and catalyzes parts of it.  

It also has other properties.  The problem with most soaps is that they grab the oils and dirt and grime and hold onto it, but if the thing it is cleaning is strong enough it breaks down the soap and then gets reabsorbed by the fabric.  Ammonia grabs it and is still broken down by the grime, but as it is breaking down it rips apart the bonds between the molecules. 

In short, I'd try soaking in Dawn soap and ammonia.

I like the smell of gas better than the smell of ammonia, but strapping it to a rack and parking it in front of a floor fan for a few days can't hurt.  I wonder if "baby clothes" laundry soap would get smells out better, babies make smells.

Don't use ammonia. While the premise is mostly correct, ammonia solutions are high pH and can damage synthetic fibers. Plus then you smell like cat pee. 
 

baby laundry soap is typically less aggressive than normal detergent. 

None of my clothes or shop rags smell like ammonia when I wash them ¯\_(ツ)_/¯   
You don't just let it dry out, you actually run them through the laundry or whatever.