No bicarbonate-containing substance or alkalizing substance that effectively alters the serum or plasma pH or concentration of bicarbonates or total carbon dioxide in a horse may be administered to a horse within twenty-four hours of post time of the race in which the horse is entered.

An official veterinarian, the board of stewards or the executive secretary acting on behalf of the commission may at their discretion and at any time order the collection of test samples from any horses either in the horse's stall or within the receiving or test barn to determine the serum or plasma pH or concentration of bicarbonate, total carbon dioxide, or electrolytes.

Test samples must not exceed 37.0 millimoles of total carbon dioxide concentration per liter of serum or plasma plus the measurement of uncertainty of the laboratory analyzing the sample. A serum or plasma total carbon dioxide level exceeding this value is a violation of this rule. Penalties will be assessed as a category B violation as provided in WAC 260-84-110.

Split samples will be taken from all horses entered to run in a race when bicarbonate testing is to be done. When split samples are taken, they will be shipped as soon as practical to the commission-approved laboratories for total carbon dioxide split sample testing. The commission is responsible for the cost of shipping and testing of split samples taken under this section.