United Blood Services, Central Coast on Wednesday issued a critical appeal for blood donors with the rare blood type O-Negative, and a serious appeal for type O-Positive.

Demand in recent days has escalated for both of these types, dropping the available supply of type O-Negative to critically low levels, with supplies of O-Positive dipping very low as well.

Donors with Type O (positive or negative) who are eligible are urgently asked to donate at their nearest center or blood drive, or to donate as soon as they become eligible. Those with other blood types are asked to keep to their routine schedule of donating three times per year, in order to maintain an ample and steady supply.

It is the red blood cells of type O blood that are in the highest demand at local hospitals. O-Negative blood is found in just 7 percent of the population. Known as the “universal donor,” this blood type can be transfused to anyone. It is often transfused in emergency and trauma situations, when there is little time to “type” a patient’s blood. Patients often need multiple units, in some cases hundreds of units.

In the case of O-Positive blood, more than 37 percent of the population has this blood type, making a match very likely. As it can be safely transfused to a patient of any blood type that is also Rh positive, it, too, is often needed. And again, multiple units may be needed by any one patient.

The blood center is especially seeking new donors who perhaps don’t know their blood type, in an effort to identify more donors with the rare O-Negative blood type. Those who have never donated are especially encouraged to come forward.

Donations may be made at the UBS Center in Santa Barbara at 902 Laguna St. Click here for a list of blood drives in the area. Appointments are appreciated, but not necessary. Walk-ins are also welcome, and will be honored as our appointment schedule allows.

Center hours are 10 a.m. to 6 p.m. Mondays and Tuesdays, 10 a.m. to 7 p.m. Wednesdays and Thursdays (pizza served on Wednesday evenings) and 8 a.m. to 3 p.m. on Fridays.

Donors must be older than age 16, weigh at least 110 pounds and be in good health. Additional height/weight requirements apply to donors age 22 or younger. Donors are asked to make an appointment by calling United Blood Services at 800.715.3699 or clicking here. Just click on “Donate Blood” and type in a ZIP code to find a list of drives nearby.

— Janna Nichols is the marketing and communications manager for United Blood Services, Central Coast.