The next blood donation clinic at my university is on Rosh Hashana and not for particular recipients. Would donating blood be halachically sound?

I don't think I could anyway because of all the signing of papers, but does it count as saving a life, thus waiving yom tov requirements?


1 Answer 1


In brief, no, this is not permissible. Two issues:

1 - See here regarding the problem of bleeding and causing a wound on Shabbat. Some say it is a prohibition of shochet - slaughtering. Others say this is a prohibition of dosh b/c blood is "extracted" from blood vessels and capillaries.

The article does specifically mention giving a blood test on Shabbat, which is "more sever" than donating blood to someone else. Even that is prohibited unless this is a case of pikuach nefesh (which I shall define, later).

You mentioned Rosh Hashanah, which is not Shabbat but a Yom Tov. The only melcahot permitted on Yom Tov are those needed for food-related preparation such as slaughtering an animal that you intend to eat on Yom Tov, itself. Donating blood is not related to eating, so it would be prohibited on Yom Tov.

2 - Pikuach Nefesh has a definition that applies to saving a specific life of someone who's life is in imminent danger. This implies two things - A) It is the life of a specific person (i.e. - not a random person whom you don't know about, and b) if you don't immediately act, that person may die.

Regarding a blood donation, you don't know about anyone whose life is in imminent danger NOW. This is a remote possibility. See this article near the middle regarding administering a smallpox vaccination (which could be more severe than a blood donation.) Citing:

Rav Shlomo Zalman Auerbach zt”l discusses the situation where a particular illness is theoretically life-threatening, but the chances of it being so are relatively slim. Does this also warrant chillul Shabbos?

He maintains that if most people would act immediately due to the urgency of the matter, then this is a case of safek pikuach nefesh and chillul Shabbos is required. However, if most people are unconcern about such an illness, chillul Shabbos is not allowed as there is no sakanah. The example that he gives is the smallpox vaccination. Although technically speaking, once the doctor says that the child needs the vaccination, one should administer it as soon as possible, nevertheless, since most people did not do so, as the need is not urgent, one is not allowed to transgress the Shabbos for it (Shu”t Minchas Shlomo, vol. II, #29.4 [in later editions: vol. II-III, 37.2]).

With a blood donation, it is quite obvious that "most people" are "unconcerned of an illness". As a matter of fact, you don't even know IF there is ANY kind of "illness" as you don't even know where your blood is going.

  • 1
    I believe it's a machlokes in mishna as to whether melachos permitted for food are allowed to be done for other things. The halachah is that it's permissible, which is why we can carry on yom tov, for example. So if blood donation has the problem of slaughtering, it should be allowed on yom tov
    – user613
    Aug 31, 2015 at 23:10
  • @user613 I'm not sure that this logic follows for everything. I think carrying was an exception made to allow that for non-food purposes. See if you can check this further and, also, link and / or point me to where this is discussed, so I can check it as well.
    – DanF
    Sep 2, 2015 at 2:41
  • Not only carrying. If not for this, you wouldn't be able to light yom tov and Shabbos candles on yom tov. I think this whole machlokes is between hilel and shamai, but I'll check it up
    – user613
    Sep 2, 2015 at 3:23
  • either way, it wouldn't apply here because you can't do something that you could've just as well done before yom tov. Also, generally, the 'melachah' has to be for that very day, with the exception of Shabbos candles, and with blood donations, the blood might be used much later.
    – user613
    Sep 2, 2015 at 3:25
  • Found it. Beitza 12a. The gemara discusses whether shechting an olah (which isn't eaten) is permitted. According to hilel yes, according to shamai, no. The reasoning is מתוך שהותרה הוצאה לצורך הותרה נמי שלא לצורך.
    – user613
    Sep 2, 2015 at 3:33

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