[Avodah] donating blood

[Danny Schoemann]

>> I've often wondered if donating blood or getting a blood test is like
>> Hakazas Dam and therefore requires Netilas Yadayim afterwards.

I wrote:
> I have seen Rabonim go "out of their way" to do so, in both cases.

I looked it up in Nekiyus V'Kavod Tefilo (by a R' Yair Yissachar
Yanai). In 2:27 he writes that R Chaim Kanievsky requires washing
after both donating blood and blood tests.

In the footnotes he mentions that RSZA (in Nishmas Adam 4:4) doesn't
require washing after a blood test as it's only a "segula" whereas
Chazal's requirement was for Refu'a, and we don't add to Chazal.

He also mentions that the Toras Hayoledes 2:2 (R Zilberstein) requires
it for blood tests also.

- Danny