Out of curiosity ...

[lesyeuxouverts]

The National Blood Service regulations for donation permanently disqualify men who have ever had sex with men, and women who in the last 12 months have slept with a man who has ever slept with a man.
If you would like to give blood but are disqualified under National Blood Service regulations (available here in a handy flash format and in text here)

Comments

[themikado]

Since I'm in Canada and have lived for more than six months in the UK during my lifetime, I'm unable to give blood thanks to the BSE scare.

[lesyeuxouverts]

Weird how the UK is singled out, regardless of the number of cases.
xxx

[friend_of_tofu]

Or the relative risk of activities, since a vegetarian is known to have died from CJD in the past.