HELP! Mustard gas created...

kikiganz

Well-known member
May 7, 2016
92
Atlanta, GA
So DH just accidentally poured liquid chlorine into the muriatic acid dispenser. He saw the cloud and ran. He realized what he did and put a ventilator and dropped a hose in the dispenser then put the lid on. Now we have no idea what to do. There is about 1 gallon of muriatic acid, 1/4 gallon liquid chlorine, and about 3/4 gallon of water in our muriatic acid dispenser and we are sitting here staring at each other. Do we just dispense it all in the pool? And then run water through it? Any suggestions? TIA
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
16,022
Tucson, AZ
It’s chlorine gas, not mustard gas and it reacts instantly and is likely gone by now. They are two different things. You’re husband is lucky he didn’t blow himself up as chlorine gas at high concentrations is not only poisonous but explosive. This could have been A LOT worse.

Carefully open the lid and let it vent. Overflow it with water from a garden hose while standing way back. Let it overflow for a good long time until all the acid has stopped reacting with everything. Then rinse it all away and heavily saturate the ground with hose water. The acid will react with the soil in the ground around the containers. If the container is near your house’s foundation, you’ll want to make sure everything is wetted and I would even dump a bunch of baking soda all around to help neutralize the acid. Use baking soda, NOT soda-ash.

Based on the added amounts, almost all of the LC converted into chlorine gas and escaped. So what you have now is “salty” acid.
 
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JamesW

TFP Expert
Mar 2, 2011
16,752
You could also use borax to neutralize the acid. Baking soda or sodium carbonate will work but will foam and bubble.

You can use hydrogen peroxide to neutralize the chlorine.

I would probably put a quart or two of hydrogen peroxide in first slowly and then add the borax.

Be super careful and do not risk exposure to the fumes.
 
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kikiganz

Well-known member
May 7, 2016
92
Atlanta, GA
It’s chlorine gas, not mustard gas and it reacts instantly and is likely gone by now. They are two different things. You’re husband is lucky he didn’t blow himself up as chlorine gas at high concentrations is not only poisonous but explosive. This could have been A LOT worse.

Carefully open the lid and let it vent. Overflow it with water from a garden hose while standing way back. Let it overflow for a good long time until all the acid has stopped reacting with everything. Then rinse it all away and heavily saturate the ground with hose water. The acid will react with the soil in the ground around the containers. If the container is near your house’s foundation, you’ll want to make sure everything is wetted and I would even dump a bunch of baking soda all around to help neutralize the acid. Use baking soda, NOT soda-ash.

Based on the added amounts, almost all of the LC converted into chlorine gas and escaped. So what you have now is “salty” acid.
Good to know. We immediately text our pool installer and he said "DUDE. YOU JUST MADE MUSTARD GAS! GET AWAY!" So our nerves are shot. Thanks for the advice. He wouldn't give us any (liability blah blah blah) and so we were stuck. We have plenty of baking soda so we will dump it everywhere before proceeding. Thanks again.
 

JamesW

TFP Expert
Mar 2, 2011
16,752
Don't seal the container so that it is airtight. If any gas is generated, it can cause pressure. So it needs to be able to vent.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
16,022
Tucson, AZ
Not that I don't agree with the chemistry that @JamesW posted, I just simply wouldn't create any more of a hazard than is necessary by messing with adding powders to liquids. Acid/base neutralization reactions can be very exothermic especially when concentrated chemicals in the forms of powder and liquids are involved. There's no telling if the heat generated from the neutralization will cause boiling or evaporation. Baking soda will turn into salt and carbon dioxide which the soil will tolerate. Borax will turn into salt and borates and the excess boron could leave you with a dead patch for a long time.

The best method is to simply dilute the heck out of it and let it spill on the ground. Muriatic acid is not going to last long when in contact with soil and it will begin to neutralize rapidly. If there is baking soda around, that will work fine too to help speed up the neutralization but it's not necessary either. Treat it like the HAZMAT team would - get the garden hose(s) and soak the heck out of it while diluting it away.
 

JamesW

TFP Expert
Mar 2, 2011
16,752
I would be concerned about the concrete and equipment around the tank if acid were to get on everything.

Maybe just neutralize the chlorine with hydrogen peroxide and use the acid as usual.

I have added hydrogen peroxide directly to bleach with no problem. I think that it was endothermic and the mixture ended up cooler.

You will know that the reaction is complete when adding more hydrogen peroxide does not bubble.
 

JamesW

TFP Expert
Mar 2, 2011
16,752
As Joyfulnoise noted, the reaction would be fast. So, there might not have been much chlorine left once the gas dissipated. The solution might have been useful once the residual chlorine was neutralized.

For future reference, if anyone has a chemical spill or incident that they don't feel comfortable dealing with, contact your local hazmat team for advice and response.