PDFWAC 260-70-635

Environmental substances.

Certain substances can be considered "environmental" in that they are endogenous to the horse or that they can arise from plants traditionally grazed or harvested as equine feed or are present in equine feed because of contamination or exposure during the cultivation, processing, treatment, storage, or transportation phases. Certain drugs are recognized as substances of human use and could therefore be found in a horse.
(1) The following substances are permissible in test samples up to the stated concentrations:
Arsenic - 0.3 mcg/ml urine
Caffeine - 100 ng/ml serum or plasma
Cobalt - 50 ppb serum or plasma*
*
A level of 25 ppb in serum or plasma will result in the horse being placed on the official veterinarians list until such time as the level drops below the 25 ppb.
Benzoylecgonine - 50 ng/ml urine
Estranediol - 0.045 mcg/ml free + conjugated (5a-estrane-3β,17a-diol), in the urine of male horses, other than geldings
Gamma aminobutyric acid (GABA) - 110 ng/ml in serum or plasma
Hydrocortisone - 1 mcg/ml urine
Methamphetamine - 10 ng/ml urine
Methoxytyramine - 4 mcg/ml, free + conjugated urine
Morphine glucuronides - 50 ng/ml urine
Salicylate salicylic acid - 750 mcg/ml serum or plasma
Theobromine - 2 mcg/ml urine
Tramadol - 50 ng/ml urine
(2) If a preponderance of evidence presented shows that a positive test is the result of environmental substance or inadvertent exposure due to human drug use, that evidence should be considered as a mitigating factor in any disciplinary action taken against the trainer.
[Statutory Authority: RCW 67.16.020. WSR 19-03-081, § 260-70-635, filed 1/14/19, effective 2/14/19.]