SURGEONS had to postpone routine operations to ensure that there was enough blood for emergency cases when the blood supply in Singapore fell 60 per cent below normal levels two months ago.

Although the situation is now back to normal, the Red Cross is calling on blood donors to give at least twice a year and wants new donors to come forward.

Madam Cecilia Tan, director of the Red Cross blood donor recruitment programme, said: 'Hospitals in Singapore use 200 units of blood per day. But we would like to have double that in the blood bank to make sure we have enough for emergencies.'

The minimum age for giving blood is 16 years, and students donate about 15 per cent of supplies in the national blood bank.

Madam Tan said the number of donations is usually 'comfortable' between March and September, when schools are in session.

Each donor gives one unit, which is between 300 ml and 430 ml of blood, and during this period, between 340 and 390 units are given every day.

Liquid blood lasts only up to six weeks. Supplies fall between October and January because of exams, school holidays, fasting and the festive season.

The SQ006 crash in Taipei last November also affected blood supplies in December and January because about 5,000 people gave blood in the week following the accident, in anticipation that the injured survivors, who were brought back here for treatment, might need transfusions.

The donors were not able to give blood again until February, because a three-month break is required between donations.

The Singapore General Hospital uses about 70 units of blood a day, according to Dr Tien Sim Leng, who heads its blood bank.

More than half of the SGH's blood stocks are used in operations, both emergency and planned. But Dr Tien said between 10 and 15 outpatients with chronic blood disorders come for transfusions every day.

At present, 43,000 people in Singapore give blood, which is less than 2 per cent of the population.

The Red Cross wants more new donors like Madam Regina Teo Swee Chin, 29, who gave blood for the first time last Thursday.

At the other end of the scale is security guard Abbas Ahmad, 52, who has given blood 102 times since 1964.

He said: 'Having seen me give blood for all these years, my 29-year-old son has also become a donor. He has given blood 20 times already.'