As we Aggies say, “Got a little story for you Ags.”
TL;DR: If you’re going to use Sodium Nitrite, protect yourself, family, pets, property, and water like all your lives depend on it. Keep activated charcoal on hand and tell the ambulance/ER they’ll need to administer Methylene Blue as fast as possible - if you think there’s any possibility of any person or animal ingesting it.
To add some information regarding the Sodium Nitrite containing fluids. Last year in my real job, we got a report of 12 dead cows after drinking a mystery purple liquid. The liquid was in three, 15 gallon containers. Cows are curious, and knocked one over, causing it to leak onto the ground. Apparently nearly all of them ended up lapping up some of the liquid, which was estimated to be about 8 gallons spilled and it had also soaked into the ground, so theoretically they didn’t drink much. The container labels were badly worn and couldn’t be identified, but it was bright purple. It took me the better part of the day, but I was able to reconstruct a label from the photos the Sheriff sent, do a bunch of Googling, and determine that it was probably boiler water corrosion inhibitor. (Used in large industrial boilers, like for an old school, hospital, etc.) I managed to match some of the label wording to an MSDS on file with the EPA from 1981, found the company in Ft. Worth, and happened to get ahold of one of their tech specialists that had worked for the company for 35+ years and was one month from retirement. He confirmed it was their product, and based on the containers and one word on the label, determined the time period they manufactured it and pulled the recipe. Back then, it contained Sodium Nitrite. I called the TxDPS forensics lab and the Vet to call the A&M lab, and it was later confirmed.
Here’s the awful part: The Vet explained that the animals had caustic burns in their mouths and esophagi, the A&M CVM pathology lab confirmed the chemical in the stomachs (but not the purple color). The animals died miserably. The small amount of NaNO2 that they ingested (maybe 8 gallons between twelve 800-1000-ish lb cows), caused the burns (it’s basic and an oxidizer) and starved their bodies of oxygen, leading to confusion, convulsions, unconsciousness, and eventually, death. They had died long enough prior to the Vet’s examination that the typical blue coloring of the mouth from oxygen starvation wasn’t observed. (Think blue baby syndrome.)
The one good thing is that the liquid was purple, for two reasons. One, I wouldn’t have been able to identify it so fast if it weren’t. Two, the purple dye was a pH indicator. The Sheriff couldn’t determine who was responsible for dumping the containers, and they were taken back to his office and put in an indoor evidence room. (As soon as I heard that, I told them to get it into an outdoor locker!) The County would have to pay for its disposal as hazardous waste. After speaking with the company rep, he confirmed that acid could be added to it to neutralize it, and it would turn clear when it was neutralized. (The adding of the acid was a dangerous process, and was monitored by a nearby university chemistry professor and EHS manager, the County emergency management coordinator, and performed by a neighboring City’s Fire Chief / Certified Hazmat Technician in Level A PPE.) Then it could be taken to a nearby city with a large wastewater treatment plant where it could be safely disposed of. (Large cities >50,000 population usually have multiple wastewater treatment processes in one or more very large plants. They are normally capable of treating Nitrates and Nitrites that naturally occur in the wastewater stream, but an influx of straight chemical has to be titrated in carefully and the plant has to be monitored during the disposal, because if done wrong, it could literally kill the plant (the microorganisms that are the entire basis of wastewater treatment; they die, and you don’t get to flush your toilet for a while). Please interpret the previous information as “do not try this at home”.
Unfortunately the owner of the cattle and the County had no one to prosecute, however the cattle that were unaffected didn’t have to be destroyed because we were able to determine the exact cause.
So, if you’re going to home brew fluid, protect yourself and your family by treating the pure chemical and mixture as if it were the most dangerous thing in your home (it could be). If you’re going to use commercial fluid, keep the SDS on hand, and teach your friends/family/coworkers to recognize the signs of Sodium Nitrite exposure (ingested or inhaled) and what to tell emergency personnel should the need arise.
Ingestion (or inhalation of excessive amounts of dust) causes rapid drop in blood pressure, persistent and throbbing headache, vertigo, palpitations, and visual disturbances; skin becomes flushed and sweaty, later cold and cyanotic; other symptoms include nausea, vomiting, diarrhea (sometimes), fainting, methemoglobinemia. Contact with eyes causes irritation. (USCG, 1999)
Ingestion (or inhalation of large amounts) causes poisoning which may produce cyanosis, marked fall in blood pressure, leading to collapse, coma, and possibly death. Irritating to skin, eyes, and respiratory tract. (USCG, 1999)
NaNO2 isn’t all bad, it has many beneficial uses, but I’ve already got enough dangerous chemicals lying around, so I’m not going to stock one that is apparently delicious. Personally, I’m going to try a propylene glycol based fluid, I have a couple of gallons of it, it’s harmless, and easy to find at any feedstore: https://www.tractorsupply.com/tsc/product/ideal-animal-health-usp-propylene-glycol-1-gal