Well, no, it’s not ethical because it is discriminatory to pregnant women, gay men, those with certain medical conditions, lifestyle choices and religious beliefs.
Everyone who cannot donate blood or whose blood is not acceptable to the Red Cross is not eligible for the extra credit, that list includes:
Jehovah’s Witnessness
People who weigh less than 50kgs
Anaemics
Those with blood bourne diseases
Those who are on medications preventing them from donating blood
Pregnant women
Those with a sexual preference or lifestyle that prevents them donating blood
Those who have travelled to a malaria endemic area in the last year
Those who are at risk from nvCJD
Those with new tattoos
Those who have donated blood too recently to donate again
If the only reason you can’t get the credit is because you can’t donate blood, and the only reason you can’t donate blood because you’re a a gay man or a pregnant woman…well, it’s not ethical, is it?
Don’t suggest donating blood anyway and then putting a sticker on it telling them not to use it- that’s a waste of everyone’s time and resources, and there is always a risk that the unusable blood will get used. It’s still not feasible for the visibly pregnant, anaemic, or the too slim as the Red Cross simply will NOT allow them to donate.
Also, if there was a “get out” clause, whereby you could attain the extra credit by getting the Red Cross to sign something saying you aren’t able to donate, it still violates your right to privacy by alerting the professor to the fact that there is some reason why you are unable to donate blood.
I can understand the volunteering for 2 hours as an alternative, but again, what exactly the volunteering entailed might be discriminatory to some students such as those with disabilities, illnesses, certain religious beliefs or those who already have commitments and can’t spare the time (childcare/extra jobs etc). The mere fact that the student needed to volunteer rather than give blood might require them giving the prof personal or private information that he has no right to.
Better just to stand up and say “Giving blood is a really good thing to do. The blood wagon is in town, we’re seeing which department can give the most, let’s show them how great this department is! I encourage everyone who is able to do so to give blood”.
No coercion, no “purchasing” of blood products, lots of free will.