Canadian Blood Services said it needs 32,000 donations before Labour Day to keep its supply at a “comfortable” level.

The organization put out an urgent appeal on Friday for Canadians to roll up their sleeves after the national inventory dropped significantly over the summer.

“This happens to us almost every summer as regular donors get out of that regular routine,” David Patterson, director of donor relations in the B.C. and Yukon region, told CTVNews.ca Sunday.

While fewer people donate blood over the summer months, Patterson said the demand for blood remains constant. In turn, he said CBS needs to rebound its inventory to an adequate level.

“We have a high confidence in the Canadian public. We’ve had success when we’ve reached out in the past because people understand how important it is,” Patterson said.

CBS says it’s in need of all blood types but is particularly looking for donors with O-negative blood, which is compatible with all types. People can donate across the country as CBS shares its national supply.

The current shortfall also touches on the ongoing challenge of a dwindling donor base.

“Blood services are losing about 30 per cent of donors over the years and Canada is no different,” Patterson said.

CBS is aiming to recruit 100,000 new donors across Canada in the coming year. Its largest demographic of donors are over the age of 50 but it is also hosting clinics on school campuses to inspire a new generation of donors.

Canadians can book an appointment at their nearest clinic through CBS’ website. Patterson recommends people donate before the long weekend but says donations are welcome at any time since there is a constant need for blood as it is only usable for 42 days.