If an Iowa worker tests positive for a drug test, can the Iowa employer deny benefits for a Workers' Compensation claim?

There is a possibility that the Iowa Work Comp benefits could be denied.  Here is what the Iowa Code reads regarding this topic:  "no compensation under this chapter shall be allowed for an injury caused by...the employee's intoxication, which did not arise out of and in the course of employment but which was due to the effects of alcohol or another narcotic, depressant, stimulant, hallucinogenic, or hypnotic drug not prescribed by an authorized medical practitioner, if the intoxication was a substantial factor in causing the injury."  Further, the Iowa Supreme Court has held the following:  "...the intoxication must have been both the cause in fact of the injury and a substantial factor in producing it."  When the case comes before the Iowa Workers' Compensation Commissioner two issues will be addressed when making a decision on the case:  1) The level of intoxication affected the worker's reason, mental ability, or judgment, or caused the loss of bodily actions or motions.  2) Whether or not the intoxication was a major factor in causing the work injury.