My refrigerator (manufactured circa 1960s) leaked all of its freon. Adjacent to the refrigerator was a stainless steel pot on a gas stove. After the leak, a series of irregular brown splotches formed on the pot, highest in concentration near the base (image attached).

The pilot lights are always lit on the stove and I am guessing that the splotches had something to do with exposure to heat. Some scrubbing with traditional dish soap removed a sticky, brownish tar, although the spots remained. These splotches also only appeared on the outer surface of the pot, which leads me to suspect the reaction may have involved grease.

I understand that freon was designed to be nontoxic, but I'm not certain about its decomposition or oxidation products. I was hoping someone could offer some insight into what exactly caused these splotches and whether they think the pot is still safe to use.

Thank you!

This is from Environmental Health and Safety on line and I am posting the whole article so you will be aware of the dangers of exposure to Freon. I would be concerned because it is a health hazard and the pot should be disposed of safety.

As for the splotches on the pot, if they weren't there before the freon leak, then you can more or less assume it was caused by the freon leak.

Freon Exposure and Your Health

Have you recently found out that your refrigerator or air conditioner has been leaking freon and you are concerned about the effect on your health?

"Freon" is not exact a chemical. "Freon" is actually a trade name that describes a whole class of chemicals used in refrigeration. Most of the chemicals included under the trade name of "Freon" are known as "chlorofluorocarbons." This means that their chemical structure is made up of the main chemical building blocks of carbon and hydrogen, but they also include chlorine and fluorine as well. With out knowing the EXACT version of freon that was used in your refrigerator, one can only comment on the general health effects of freon as a whole.

The most serious side effect of freon exposure would occur at the time of initial exposure. People who have a history of heart problems should be very concerned about Freon because it can cause cardiac arrhythmia (irregular heartbeat), and palpitations at very high concentrations. For people who have a history of heart problems, being exposed to small amounts of Freon from leaking appliances should not pose any significant health risk.

Fortunately, Freon does not have serious long term health consequences. It is not a carcinogen, teratogen, or mutagen, and it does not damage the liver. When it is inhaled, it is rapidly excreted by exhalation, and it is not significantly accumulated in the body. This means that breathing low concentrations of freon from a leaking refrigerator or air conditioner over a long period is unlikely to have a cumulative effect, and thus few, if any, long term health effects.

When trying to figure out how much Freon you have been exposed to, there are several things to keep in mind. First, there is a finite amount of Freon contained in the refrigeration system, so you can't be exposed to any more than what is actually in the system. Second, Freon is about 4 times heavier than air, so it is going to sink to the floor initially, though it is highly volatile and will disperse rapidly. What this means is that the closer to the floor that you are, the more Freon you are likely to breathe in. This is a concern especially for children and pets, children because they are smaller and thus require smaller doses for acute effects to occur, and pets, especially dogs, because they are more sensitive to the heart sensitizing effects of Freon than humans are.

If you discover that you have a Freon leak, contact a technician for repairs immediately. Open up windows and doors and use fans to help move the air out of the area. Remove yourself and your pets to an area of fresh air, and if you feel any unusual health effects, seek medical care. If you have chronic heart conditions, consider having your Freon containing appliances checked regularly for leaks.

Tick

Well, freon is relatively safe but when docomposed you get some nasty stuff capable of doing what you saw.

If it's an older refrigerator I will assume R-12. Should be marked somewhere.

Here's the MSDS for R-12: http://win14.american.edu/safety/au/...000/000627.pdf

Decomposition involves releasing hydrochloric acid (typical battery acid) and hydrofloric acid. The latter eats glass.

I can't see any reason why the pot would not be safe to use.
Acids attack metals big time.