An Austin-based appeals court didn't buy a San Antonio man's argument that the state's blood alcohol limit of 0.08 discriminates against alcoholics.

Ralph Alfred Friesenhahn argued that his four-year prison sentence for his fourth DWI conviction should be overturned because the legal driving limit discriminates against people with a higher alcohol tolerance, the Austin American-Statesman reported. He said it violates the equal protection clause of the 14th Amendment and is therefore unconstitutional.

The 3rd Court of Appeals wrote in an opinion issued Friday that because the state's limit is applied to everyone equally, it's not unconstitutional.

Friesenhahn had argued that "many folks who suffer from the disease of alcoholism are able to maintain normal functioning at 0.08 vs. a person who does not," the court opinion said.

Friesenhahn said alcoholism is a disability under the Americans with Disabilities Act, and the driving limit allows for members of the "protected class of alcoholics" to be prosecuted without showing that they lost control of their mental or physical faculties.

Alcoholics and recovering alcoholics can be protected under the Americans with Disabilities Act, allowing them to seek reasonable accommodations from their employers, such as altered work schedules, according to the U.S. Equal Employment Opportunity Commission.

The court opinion, written by Justice Cindy Olson Bourland, said Friesenhahn didn't argue that alcoholics are treated differently under the law. Rather, the court found he argued alcoholics should be treated differently, the opinion said.

Friesenhahn was arrested after a crash in Comal County, south of New Braunfels. Tests later indicated his blood alcohol concentration was 0.29, the Statesman reported.

Sammy McCrary, chief of the felony division for the Comal County criminal district attorney's office, told the Statesman the idea that the driving limit law is discriminatory is ridiculous.

"You're not being punished for being an alcoholic. It's the driving that's the problem," McCrary said. "It's making the decision to get into a 3,000-pound vehicle ... after drinking."

A prestigious panel of scientists released a report in January recommended lowering the legal driving limit to 0.05. The National Transportation Safety Board made the same recommendation in 2013.

Utah has passed a law to lower its threshold for blood alcohol concentration to the suggested 0.05, which will go into effect at the end of the year.