Mineral Oil for Cast Iron and Wooden Cutting Boards:

my question is: whether mineral oil that is labeled as USP and is 99.9% mineral oil (unflavored), but bottled and sold as “helps relieves occasional constipation” (at $1.67 for 16 oz) can be used for treating wood cutting boards and on cast iron skillets? This is as opposed to a 3-4 oz bottle of mineral oil labeled as being for wood cutting boards and selling for $8.00. I saw this at Target and I asked the pharmacist if the regular $1.67 oil was “food grade” and she said she didn’t know. Presumably it is since it is intended to be ingested, but I want to see if there were other “differences” that required me to buy the more expensive stuff.


Thanks -- Laurel Canyon Joe

The labeled as USP is fine! also used as a lubricant laxative I'm reading from the bottle I have in front of me [no jokes please.]

I use regular mineral oil for my boards and cast iron. I also give it occasionally to my cat for hair balls. Haven't tried the stuff myself.

Pam, does it seem to help your cat?

To be honest I was never very consistent with it. My cat has a terrible throw up problem, to be blunt. I can't remember how much the vet said to give him. You could google it.

Thanks, Pam...I"ll google it. Our cat has a terrible problem, too!

thanks for your input and help.

To answer your original question, the regular Mineral Oil sold in the drug stores or at WalMart, etc., is the same as the oil sold by John Boos and other cutting board manufacturers.
It is not further refined, just a marketing thing to make more money.

One manufacturer of wooden bowls used to provide a refined walnut oil for treating the (expensive) bowls they made, often custom sized, but discontinued it because of so many people who have allergies to tree nuts, especially walnuts.
I never used it, although I do have one of the bowls, because some in my family are allergic to walnuts.

Frankly, I have used walnut oil for cooking but as it rapidly becomes rancid, I don't think it is appropriate for treating wood.
Mineral oil will keep for years without alteration, as long as it is not exposed to prolonged heat.

I was using mineral oil (from Wal-mart) to season my cast iron after cleaning, but it gave off such a chemical smell that I switched to grapeseed oil (Trader Joe's), because of it's high smoke point, I like it better, less of a chemical smell. Have been using it since.

Pure mineral oil should not have a chemical smell, It should have no discernible odor at all.

I have had to drink mineral oil a few times to help get rid of barium. If you drink it, the olnly thing that cuts through it is an apple juice chaser. It is bitter and goes through you so fast that you better be near a toilet until the oli is out of your system. Now that I have told you all what you didn't want to know....