Turn a negative into a positive this Canada Day

RH negative blood is rare and inventory is low


(OTTAWA) – Preparations for Canada Day are underway and Canadian Blood Services wants people to think of blood donation as a gift to their country. We need all blood donors to book an appointment now, particularly those with Rh negative blood.

“Only about 15 percent of Canadians are negative for the Rh antigen, which means that there is an absence of a particular protein on the surface of their red blood cells,” says Dr. Tanya Petraszko, associate medical director at Canadian Blood Services. “Blood from donors who are negative for the Rh antigen is more likely to be given to patients in urgent need when there is not enough time to perform compatibility testing.”

Donors with a negative blood type, such as O- or A-, can help more patients than those with a positive Rh antigen. Only 7% of the Canadian population has O negative blood and in an emergency this blood type becomes the default that is used for transfusions. This combined with long holiday weekends means our inventory is depleted very quickly.

With Canada Day falling mid-week, fewer appointments are being booked as many regular donors are planning to take the week off.

“As we approach the holiday and looking ahead to the coming weeks, we are concerned about the high number of appointments that are still available to be booked,” says Mark Donnison vice president of donor relations. “The need for blood doesn’t take a holiday and there is an immediate need for blood donations in anticipation of coming summer vacations.”

There are plenty of opportunities to donate blood now and throughout the summer with clinics being held in communities across the country, but we need your help now. Make blood donation part of your holiday weekend, commit to this patriotic act and help hospital patients celebrate Canada Day. Book an appointment by downloading the GiveBlood App or by visiting blood.ca.

Check out the status of our national blood inventory on blood.ca.

Quick Facts

  • O negative blood is the most critical blood type and is always in very high demand because:
    • It represents such a small part of the population
    • It is the only blood type that’s compatible with all other blood types
    • O negative patients can only receive from O negative donors
    • It is used in most critical emergency situations
  • All females of childbearing age and all children for whom blood compatibility tests can’t be done (e.g. trauma) will be given group O negative blood as the safest course of action.
  • Only 15% of the population is Rh negative, but 100% of women of childbearing age and children receive Rh negative blood to ensure their safety if their blood type is unknown.


Graphic of Blood Inventory and how many days we have what is the optimal 2015