The board of directors of the Association of Racing Commissioners International on Friday unanimously adopted a model rule that will reduce the threshold level for the popular painkiller phenylbutazone, a vote that will pave the way for what may be contentious approval processes at the state level.\r\nThe new threshold level &ndash; two micrograms per milliliter of blood plasma, down from the existing level of five micrograms &ndash; was adopted following calls by state regulatory veterinarians to lower the allowable concentration of the drug because of concerns over the impact of the painkillers on raceday examinations to determine whether a horse is exhibiting signs of lameness.\r\nStates currently prohibit the administration of phenylbutazone within 48 hours of a race, but many regulatory officials were concerned that the higher threshold level was encouraging horsemen to administer the drug inside that window.\r\n&ldquo;We&rsquo;re not interested in creating a system that catches a bunch of trainers,&rdquo; said Ed Martin, the executive director of the RCI, an umbrella group for racing commissioners. &ldquo;We&rsquo;re interested in giving our regulatory veterinarians the best chance to conduct a clean exam.&rdquo;\r\nRepresentatives of horsemen&rsquo;s groups had spoken out in opposition to the lower threshold level, contending that the racing industry had not conducted enough scientific studies to support the change and that the new level will lead to a rash of positives in horses that had been administered the drug within the industry&rsquo;s existing rules.\r\nKent Stirling, the executive director of the Florida Horsemen&rsquo;s Benevolent and Protective Association and the chairman of the National HBPA&rsquo;s medication committee, said on Friday after the approval that horsemen did not plan to challenge the lower threshold at the state level.\r\nHowever, he said that most horsemen would push for amendments to the recommended penalties for phenylbutazone positives when the concentration of the drug is near the threshold level. &ldquo;We&rsquo;re still unhappy with the way it was done, because we don&rsquo;t think there&rsquo;s a preponderance of scientific evidence&rdquo; for the new level, Stirling said. &ldquo;But right now we think that it&rsquo;s doable as long as the penalty scheme starts at a much higher level.&rdquo;\r\nCurrently, a first-time positive for phenylbutazone &ndash; commonly known under the trade name Butazolidin, or Bute &ndash; typically draws a $250 or $500 fine and the loss of the purse earned by the horse. The drug is considered a Class 4 medication, a drug that has limited ability to impact racing performance and is mostly used as a therapeutic, under the RCI&rsquo;s classification system.\r\nMartin said directors discussed the possibility of amending the penalty guidelines during the conference call on Friday in which the directors voted to approve the lower threshold. In that discussion, directors said that the penalty for a first-time offense could be reduced to a warning, if the concentration was near the threshold level. &ldquo;We&rsquo;ve listened to some of the horsemen&rsquo;s concerns and we plan to take that under advisement,&rdquo; Martin said.