In certain instances, I've heard rabbis allow soaps and harsh cleaners to be used to make food and food-residue "Pagum" (ruined), which then removes any prohibition that might otherwise result when the taste of the food is transferred to other objects.

But how harsh does the cleaner need to be? If I have non-toxic, biodegradable soap for my dishes, do I need to be more careful when washing the dishes to ensure that the food residue doesn't transfer taste, via the hot water I'm using to wash the dishes, to the sink or other utensils that might be nearby?

Is there a difference between meat/milk/Issur and Ḥametz?

This occurred to me at work, where there is a sink I can use to wash my dishes, but I noticed that the cleaners are specially designed to not harm the environment. I exclusively use disposable dishes and utensils at work, but the thought crossed my mind that this could pose a problem if I washed anything under hot water in the sink.

I've also learned that pouring hot liquid (oil from a frying pan, for example) into the trash can be a Bishul problem if there are edible milk and meat residue in the trash, but that the Pagum principle can be used to obviate this problem.

  • 1
    IIUC pagum doesn't stop taste transfer. It just makes the transferred taste not prohibitive
    – Double AA
    Apr 12, 2013 at 15:53
  • Actually, virtually all soap is non-toxic and biodegradable. Soap tastes nasty though - even saponified fat (which is presumably the type you are talking about, as apposed to sodium lauryl and laureth sulfate). But make sure it's made from kosher oil, and not tallow. If you see tallowate it's treif. Many natural bar soaps are made from tallowate and it's questionable if you are allowed to wash yourself with that. (And I would definitely never use it for dishes.)
    – Ariel
    Apr 12, 2013 at 19:01
  • @Ariel, if it's N"T LiFgam, what difference does it make what it's made of?
    – Seth J
    Apr 12, 2013 at 19:04
  • When they say "harsh" in reference to soap they mean residual lye in the soap which was a problem a long time ago. These days manufacturers are much more accurate in measurement and no lye is left. Non fat-based soaps (i.e. the regular cheap kind) never have a problem with lye. (So be careful when using halchas that mention soap being harsh - it's not anymore, none of it. But it does still taste bad.)
    – Ariel
    Apr 12, 2013 at 19:05
  • @SethJ Um - why are you asking me? Isn't that what your question assumes, that it does make a difference?
    – Ariel
    Apr 12, 2013 at 19:05

1 Answer 1


The soap in your work is probably not strong enough to be Pogem. See Eli Gerstner's article titled "Kashering with Sha’Ar mashkim" (page 5 of the pdf):

The Orchas Chaim says that water mixed with ash (a form of caustic) is also considered sha’ar mashkim. This mixture has the added advan- tage that it is pogem all the bliyos that it is maflit (Shulchan Aruch Y.D. 95:4) and in cases of great need, it can be used to kasher ben yomo kailim. Although Shach (95:21) questions whether ash water is sufficiently pagum, later poskim [Chazon Ish Y.D. 23:1; see also Igros Moshe Y.D. II:31] agree that today’s caustic solution (1-2% caustic soda which is what is commonly used) are sufficiently pagum.

Wikipedia Article on Caustic Soda

  • BYW Caustic Soda is also called lye.
    – Ariel
    Apr 12, 2013 at 22:00

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