The South African National Blood Service (SANBS) said on Tuesday it was scrapping its controversial use of race as a risk factor when assessing if a donor’s blood was safe or not.

The move comes after an uproar late last year when it emerged that blood donated by President Thabo Mbeki had been destroyed because he did not complete a mandatory questionnaire and his race placed him in a high-risk category.

SANBS had a policy of incinerating blood donated by blacks, who constitute about 75 percent of the population, because of a perceived high HIV prevalence rate among this group.

“The new model removes race as an indicator of risk and replaces it with one based on the number and frequency of donations over a two-year period as the key criterion,” the SANBS said in a statement after a meeting with officials from the department of health.

“The theory is that with each repeated donation, risk of transmissible diseases declines. This model is being fine-tuned to see whether additional indicators should be used to guarantee safety standards,” it said.

Around 5.3 million of South Africa’s 45 million people are infected with HIV.

“The (new) model goes hand in hand with the introduction of new technology ... which is more sensitive to viruses,” the SANBS said.

The most important threat to the safety of a blood supply is the so-called “window period” as normal laboratory tests cannot detect viruses such as HIV in the first days after infection. The SANBS said the new technology will shorten the window period.