TORONTO - Canadian Blood Services and several nurses unions are at odds over a proposal to reduce the number of nurses working at blood donor clinics across the country.

The blood agency said safety remains its No. 1 concern as it makes plans to introduce changes prompted in part by difficulties in finding and keeping nurses. Regulatory approval from Health Canada would be required, but Canadian Blood Services is hoping to start moving on the plan in the fall.

The Ontario Nurses' Association said the decision to gradually replace registered nurses who perform health screening and assessments of blood donors will risk the safety of the country's blood supply.

"HIV, hepatitis C, hepatitis B -- there's many, many different diseases that are blood-borne, and we as the registered nurses are in the position to do an appropriate assessment," ONA president Linda Haslam-Stroud said in an interview Tuesday.

"We're looking for symptoms of illness, pregnancy, diabetes, low hemoglobin, confidential information in relation to sexual behaviour -- all those types of things."

Nurses have the authority to defer a patient if they are concerned that there could be a risk to the blood supply, Haslam-Stroud said.

She noted that a registered nurse has a four-year university education, and the blood agency is planning to use people with a high-school education to do screening instead.

"We are very concerned that by not having that kind of skill level of a registered nurse, that our patients' blood supply is going to be at risk," Haslam-Stroud said.

Nurses unions in Nova Scotia and Newfoundland and Labrador have also expressed concerns about the agency's intentions.

But Canadian Blood Services countered that the nurses' concerns are unfounded, and it would never make changes that would introduce elements of risk.

"Thoroughly trained clinic assistants and phlebotomists are equally capable of assessing donor eligibility and drawing blood and plasma from people," it said in a statement Tuesday.

Those performing the screening will receive on-the-job training, in addition to classroom training. There would still be at least one nurse consultant and one nurse supervisor per clinic to help deal with any out-of-the-ordinary cases during assessment, Canadian Blood Services said.

Approximately 580 nurses currently work at the blood donor clinics in every province except Quebec.

Canadian Blood Services said it's bringing in a new operating model gradually that won't involve involuntary layoffs. Rather, the transition will take place over several years through an annual attrition rate of about 15 per cent.

The planned changes are mainly intended to deal with difficulties attracting and retaining qualified nurses, it said.

"Even today, the escalating nursing shortage has challenged our organization's ability to collect blood and blood products in some areas of the country," the statement said.

The changes would allow flexibility to move staff from one station to another within a clinic, reduce bottlenecks and make better use of donors' time, Canadian Blood Services said.

But Haslam-Stroud said poor decisions are being made.

"We believe that they need to stop the watering down of the skill level of the professionals that are doing the blood screening," she said.