# Disposal of old cooking oil **URL:** \ **Category:** Factual Questions\ **Created:** [March 25, 2012, 8:54am UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749 "2012-03-25T08:54:50Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Myglaren](https://avatars.discourse-cdn.com/v4/letter/m/f1d935/32.png) [@Myglaren](https://boards.straightdope.com/u/Myglaren)\ **Post date:** [March 25, 2012, 9:16pm UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/21 "2012-03-25T21:16:52Z")
Have a look what [Wikipedia](http://en.wikipedia.org/wiki/Soap) says about soap. Not as simple as one might think. Please don’t chuck that oil down the drain though. As some have already said the simplest procedure would be to pour it into suitable containers and add it to the trash - which is what I always used to do, kept the original bottles for just that. I wish I’d known then about running diesel engines on it though, as I had just such a car. I hardly use any oil these days and there is never any to dispose of. ---
**Author:** ![VOW](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/vow/32/3043_2.png) [@VOW](https://boards.straightdope.com/u/VOW)\ **Post date:** [March 25, 2012, 9:20pm UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/22 "2012-03-25T21:20:41Z")
I think liquid drain cleaner is concentrated chlorine bleach. I would NOT leave that in a sealed container in a closet. Out in the garage or on a back step (as long as there are no kids around) would be a better choice. Do not let this Mister Wizard concoction come into contact with any acid. ~VOW ---
**Author:** ![Washoe](https://avatars.discourse-cdn.com/v4/letter/w/ecae2f/32.png) [@Washoe](https://boards.straightdope.com/u/Washoe)\ **Post date:** [March 25, 2012, 9:43pm UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/23 "2012-03-25T21:43:44Z")
Killjoy. OK, it’s out in the driveway on top of my workbench. No kids around. 😛 ---
**Author:** ![jasg](https://avatars.discourse-cdn.com/v4/letter/j/f0a364/32.png) [@jasg](https://boards.straightdope.com/u/jasg)\ **Post date:** [March 25, 2012, 9:46pm UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/24 "2012-03-25T21:46:18Z")
Now about recycling it with a biodiesel company? If not, mix with kitty litter or other absorbent and discard in trash. ---
**Author:** ![Moonlitherial](https://avatars.discourse-cdn.com/v4/letter/m/4bbf92/32.png) [@Moonlitherial](https://boards.straightdope.com/u/Moonlitherial)\ **Post date:** [March 25, 2012, 10:39pm UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/25 "2012-03-25T22:39:02Z")
> [@sitchensis](#): > > If you can’t take it to the country and pour it in a yard. I would get the biggest pots I have and boil a bunch of water. I would then run my tap on hot for a while before pouring the oil in and follow up that with the boiling water. Don’t do that, it only delays the clog for a few meters which means the street in front of your house is going to be dug up while they clear the clog there. I save a few bottles under the sink for things like this and just fill them up, cap them tightly and dispose in the garbage. It’s frowned upon as the correct method here is to bring it to the hazardous waste disposal site (oils and batteries stall) and let them deal with it correctly. ---
**Author:** ![Tom\_Tildrum](https://avatars.discourse-cdn.com/v4/letter/t/e95f7d/32.png) [@Tom\_Tildrum](https://boards.straightdope.com/u/Tom_Tildrum)\ **Post date:** [March 25, 2012, 10:49pm UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/26 "2012-03-25T22:49:46Z")
You could make several slow-burning, yummy-smelling Molotov cocktails. (For lawful uses only, of course). ---
**Author:** ![Sudden\_Kestrel](https://avatars.discourse-cdn.com/v4/letter/s/ecd19e/32.png) [@Sudden\_Kestrel](https://boards.straightdope.com/u/Sudden_Kestrel)\ **Post date:** [March 25, 2012, 10:50pm UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/27 "2012-03-25T22:50:30Z")
> [@sitchensis](#): > > If you can’t take it to the country and pour it in a yard \ Please don’t do this. The country people don’t like it, and we have weapons. As for the OP’s problem, if you have an old coffee can (or whatever they call those plastic things coffee comes in nowadays), stuff in some waste paper you need to get rid of and then poor in the oil and pop on the lid. The paper will soak up the oil enough that it won’t be a spill hazard in your trash bag. ---
**Author:** ![Woodenspoon](https://avatars.discourse-cdn.com/v4/letter/w/bc79bd/32.png) [@Woodenspoon](https://boards.straightdope.com/u/Woodenspoon)\ **Post date:** [March 25, 2012, 11:15pm UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/28 "2012-03-25T23:15:40Z")
i just remember watching documentaries on the sewers our infrastructure is old, and stuff like oil/fats really screw up what we do have down there, its just a bad idea. just get rid of it bit by bit in old food containers/jars you can throw out with the trash. ---
**Author:** ![janeslogin](https://avatars.discourse-cdn.com/v4/letter/j/df788c/32.png) [@janeslogin](https://boards.straightdope.com/u/janeslogin)\ **Post date:** [March 25, 2012, 11:27pm UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/29 "2012-03-25T23:27:38Z")
If you cannot put in a plastic bottles and trash it then thoroughly mix it with about 250ml of pure dishwashing liquid and flush it. ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [March 25, 2012, 11:52pm UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/30 "2012-03-25T23:52:56Z")
> [@Washoe](#): > > I know it’s ridiculously easy (they do it in freshman expository chem classes at community colleges all the time, and believe me—sometimes we’re talking about people who can barely spell their own names), but how exactly do you make soap? What I’m thinking here is not specifically that **njtt** actually make soap for his own use, but that if there were some way that he could just mix it with Draino and POOF, it instantly solidifies, it would be much easier to handle and package for disposal. Just google “cold process soap” and you’ll get a pretty good idea. Basically each sort of fat has its own value on some table, and based on those values, the soap makers put in some measured amount of sodium hydroxide (lye) solution that they’ve usually made from water & Red Devil lye. Then they either boil it or blend it together to start that reaction, and once it’s started, they let it “ripen” for some period of time so that all the sodium hydroxide is reacted with something, and there isn’t any free NaOH to burn anyone. It takes a while to solidify though; the fats and solutions have to be at some moderately warm temperature first. Then they cut it up and use it. ---
**Author:** ![jasg](https://avatars.discourse-cdn.com/v4/letter/j/f0a364/32.png) [@jasg](https://boards.straightdope.com/u/jasg)\ **Post date:** [March 26, 2012, 1:17am UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/31 "2012-03-26T01:17:46Z")
Here you go, DIY [biofuel](http://www.economist.com/node/21540981). ---
**Author:** ![Woodenspoon](https://avatars.discourse-cdn.com/v4/letter/w/bc79bd/32.png) [@Woodenspoon](https://boards.straightdope.com/u/Woodenspoon)\ **Post date:** [March 26, 2012, 4:12am UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/32 "2012-03-26T04:12:07Z")
Yea 3 liters is just about enough that someone might bother to pick it up if you put an ad up on craigs list…just tell them to pick it up from the curb and leave it in some old milk jugs or something. ---
**Author:** ![chacoguy](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@chacoguy](https://boards.straightdope.com/u/chacoguy)\ **Post date:** [March 26, 2012, 5:19am UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/33 "2012-03-26T05:19:34Z")
[My work here is done.](http://www.youtube.com/watch?v=GbMdEPJiaB0&feature=related) ---
**Author:** ![purplehorseshoe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/purplehorseshoe/32/2996_2.png) [@purplehorseshoe](https://boards.straightdope.com/u/purplehorseshoe)\ **Post date:** [March 26, 2012, 7:48pm UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/34 "2012-03-26T19:48:03Z")
If you have a cat, you can pour it into the bag of used litter and then dispose of the whole mess that way. ---
**Author:** ![Quercus](https://avatars.discourse-cdn.com/v4/letter/q/7ab992/32.png) [@Quercus](https://boards.straightdope.com/u/Quercus)\ **Post date:** [March 26, 2012, 8:48pm UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/35 "2012-03-26T20:48:09Z")
> [@njtt](#): > > I have a deep-fryer containing about 3 liters of cooking oil that is now getting old and nasty. We are always told not to pour it down the sink. What would be the consequences if I did? (Since you’re in a multi-floor flat, I’m assuming your flat is connected to a sewer line, not a septic system) 1. It might clog up a sewer drain pipe – either in your house, in the street in front of your house or farther away. In the first case, it would be inconvenient for you and a cost for you (or your landlord), in the second it would be inconvenient for you (road might get dug up, you might have sewage backing up into your flat, etc.). In the third, no direct consequences, but your water/sewer rates will be fractionally higher, since it ain’t free to dig up/roto-root pipes. 2. Even if it stays liquid, it could add to problems at the sewage treatment plant. Too much oil is a major pain in the tuckus for the folks running the plant, for a variety of reasons. Again, potential higher water/sewer costs. 3. In most places in the U.S. (not sure about them furrin’ places, but I assume it’s going to be similar), you’re theoretically liable to fines from the sewage utility. They don’t like the above problems that fats/oil/grease cause, and will go after people causing problems. A one-time dump of a few liters is probably beneath their notice (restaurants are the typical offenders in these programs), but it’s theoretically possible. I’d put it in soda bottles in the trash (or whatever empty containers you have). Or try and find a biofuel maker near you who might take it, but three liters is probably not worth a lot of people’s time. BTW, where are you that you live in a second-floor flat with no yard, but foxes are a problem? ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [March 26, 2012, 9:54pm UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/36 "2012-03-26T21:54:57Z")
I used to pour the remains of the frying pan grease down the sink back when I was young and foolish. Even with limited batchelor cooking and a lot of hot water running, eventually it clogged solid below the basement cleanout before the main drain. bit of hand-router and eventually the drain was unplugged, then frequent Drano until it ran better. Now I pour the stuff into a used plastic container into the fridge, and toss it with the garbage. (Beef grease at least gets nice and hard.) That’s my suggestion for your problem. If you have a funnel, the 2-litre pop bottles sound like your best bet - less likely to leak. If you can find a bio-alternative, go for it. The trouble with using it in vehicles, I imagine, is that it could harden in cold weather and there could be bits needing filtering… ---
**Author:** ![Redfishhunter930](https://avatars.discourse-cdn.com/v4/letter/r/df705f/32.png) [@Redfishhunter930](https://boards.straightdope.com/u/Redfishhunter930)\ **Post date:** [March 26, 2012, 11:27pm UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/37 "2012-03-26T23:27:16Z")
First off remember its biodegradable so you could pour it on the ground and it will degrade The best way I’ve found especially in winter time is to mix it with old bread and bread crumbs and feed it to the birds. They go bat shit crazy on the stuff ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [March 28, 2012, 4:26pm UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/38 "2012-03-28T16:26:34Z")
> [@Quartz](#): > > Don’t pour it down the toilet or sink unless you like blocked drains. > > Can’t you use it as bonfire fuel or something? Yeah, I will have a bonfire in my upstairs flat with no backyard. Thats the ticket! > [@WotNot](#): > > What I’ve done in the past, when I’ve had a large quantity of oil to dispose of, is poured the oil into empty screw-top plastic milk or fruit juice jugs, and put it in the bin. Yes, I guess that is what I need to do, and hope that the foxes do not find it and bite it open so that it spills all over the sidewalk. Mostly the trash bags left out seem to survive (that is, there is not _too much_ stuff spread around the street after collection day). Maybe if I refrigerate the jug of old oil before throwing it out, that will help a bit. Thanks to you and all the other people who suggested something similar. > [@Quercus](#): > > . . . . > > BTW, where are you that you live in a second-floor flat with no yard, but foxes are a problem? In a medium sized town in the U.K. [Urban foxes](http://www.discoverwildlife.com/sites/default/files/imagecache/800px_530px/gallery/Urbane%20Fox2.jpg) are endemic in most towns (and even big cities) in Britain now. Incidentally, there _are_ back yards (or gardens, as the people here would call them) all along this street. I just do not have any access to the one belonging to this house. The people in the downstairs flat have access, but I do not fancy asking them if I can get through to their garden so I can pour waste oil out there. ---
**Author:** ![Sudden\_Kestrel](https://avatars.discourse-cdn.com/v4/letter/s/ecd19e/32.png) [@Sudden\_Kestrel](https://boards.straightdope.com/u/Sudden_Kestrel)\ **Post date:** [March 28, 2012, 4:57pm UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/39 "2012-03-28T16:57:42Z")
> [@njtt](#): > > Yeah, I will have a bonfire in my upstairs flat with no backyard. Thats the ticket! Well, it \*would \*solve the problem. You know, what baffles me about the whole situation is that you don’t have any trash bins. Is this a cost-saving decision by your city or is it just “the way things are done?” Even in our fairly remote location, our trash hauler provides a container. An unprotected bag of trash wouldn’t last 2 hours here, what with coyotes, raccoons and wandering bands of dogs. ---
**Author:** ![Woodenspoon](https://avatars.discourse-cdn.com/v4/letter/w/bc79bd/32.png) [@Woodenspoon](https://boards.straightdope.com/u/Woodenspoon)\ **Post date:** [March 30, 2012, 1:04am UTC](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749/40 "2012-03-30T01:04:56Z")
I wonder how long it would take to burn 3 liters of oil anyways, many times things just don’t burn as quickly as you’d imagine. [Previous page](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749.md?page=1) [Next page](https://boards.straightdope.com/t/disposal-of-old-cooking-oil/616749.md?page=3)