In article ,
polygonum writes:
Mr Medway or anyone else, do you have any advice on removing blood marks
from off-white wool-blend carpet?

Although quite some attempt was made to clean them up at the time,
various circumstances have resulted in them still being visible some 3/4
weeks later.

(No criminal aspect to this! Illness, unfortunately.)

Unfortunately, the longer left, the harder to remove.
If it's still red, I would try dampening with plain soap (not coloured)
and water, leave for a while (but keep damp), and then try blotting off.
If it's brown, then the iron in the blood is now rust, and that's harder
to remove. Things like phosphoric acid will react with it, but the
resulting products may be no easier to remove from a white carpet.
Clear vinegar (acetic acid) may dissolve it, although you might get a
resulting green iron compound which may or may not easily blot up.

Whatever you try, testing it on a hidden area is probably a good thing,
in case it reacts with anything else in the carpet.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]