Aiming to put an end to cane burning in Hawaii, a Maui group has filed suit against the state Department of Health claiming that the regulatory system that allows open-air agricultural burning is unconstitutional.

Stop Cane Burning filed the complaint Wednesday in Environmental Court on Maui, seeking an injunction that would prevent Hawaiian Commercial & Sugar Co. from burning cane in the harvesting of its 36,000-acre Central Maui plantation.

The 143-year-old Alexander & Baldwin Inc. subsidiary — the last remaining sugar grower in the state — isn’t even mentioned in the complaint. Instead, the suit focuses narrowly on the state and its regulatory arm, the state Health Department.

“The level of frustration has grown over the years,” said Kihei resident Brad Edwards, one of the plaintiffs. “The Department of Health is not doing its job in regulating the industry, and it was time to do something.”

Karen Chun, who leads Stop Cane Burning, said the state banned backyard burning on Oahu in 1973 and outlawed it on all islands in 2012, calling it a nuisance that creates a health risk due to smoke and air pollution.

“Does it make sense that backyard burning is banned as a health risk but HC&S is allowed to burn 36,000 acres six days a week, nine months per year?” Chun asked in a news release.

According to the suit, the state Air Pollution Control Act lacks any standards upon which the Health Department may lawfully adopt rules, which it says makes the agricultural burning rules that were adopted by the department unlawful and in violation of the state Constitution.

In addition, the suit claims that the permitting of agricultural burning violates state constitutional rights to a clean and healthful environment, and is a breach of the public trust protected under another section of the Constitution.

What’s more, exempting agricultural burning from the state’s general ban on open-air burning is “an irrational classification” in violation of the equal protection clause of the Constitution, according to the suit.

Finally, the suit argues, the Health Department failed to consider the Hawaii Environmental Policy Act when it promulgated its agricultural burning rules, and therefore they are invalid.

A spokeswoman for the Health Department declined to comment, saying the agency received notice of the lawsuit Thursday.

“We take our responsibility to protect the public very seriously, and the department will continue to work with residents, HC&S, elected officials and government agencies to listen to and address the concerns of the community,” Janice Okubo said in an email.

In a move unrelated to the lawsuit, the Health Department is taking written comments through Aug. 29 on the current 2015-2016 HC&S burn permit. Comments will be accepted at the department’s Honolulu office, 919 Ala Moana Blvd., Room 203, Honolulu, HI 96814.

Nolan Hirai, manager of the department’s Clean Air Branch, said the reason for soliciting comments is to address community concerns and make improvements to the HC&S burn permit. He said the comment period was requested by a few community members.

Hirai said the branch is still investigating a May 27 HC&S burning incident in which cane smoke reportedly blanketed sections of Kihei downwind of the sugar plantation.

The episode apparently helped fuel attendance at a June 25 “talk story” meeting on cane burning at the Kihei Community Center.

“We were expecting 200 people. That would have been awesome,” said Deborah Mader, one of the organizers of the meeting. “Instead, we had estimates ranging between 600 and 700 people, which is unheard of for a community meeting in Kihei. It was amazing the amount of people who came.”

Joe Ritter, a scientist from Kihei, said too many people on Maui have respiratory problems exacerbated by excessive smoke and dust from the cane fields.

“How many people have to be rushed to the hospital?” he said. “On Maui everyone is a smoker whether they like it or not. We have a right to clean air.”

Rick Volner, general manager of HC&S, said he wouldn’t comment on the lawsuit itself because he hadn’t had a chance to review it.

However, Volner did say in an email that agricultural burning as a harvesting method is common throughout the U.S. and around the world and is allowed in every state.

He said HC&S is continually making changes to its burning practices in an effort to minimize the effects of cane burning.

The current permit, covering some 150 burns per year, is a nearly 100-page document of specific protocols, field by field, that must be followed before a burn is made, Volner said.

“Compliance with all conditions of our permit is a top priority,” he said. But there are times, he conceded, when wind conditions do not turn out as predicted and a burn affects residents, “and for that we are very apologetic.”

Volner said HC&S has for decades searched for alternative harvesting methods and crops that would enable the company to stop agricultural burning.

“We thoroughly investigated mechanical harvesting, conducting a sizable pilot test at HC&S, and investing more than $2 million in new equipment and mill conversion. We have test-planted 1,000 acres of one-year cane for four crop cycles, only to find that our yields dropped to one-third of their normal levels, and operating costs increased significantly. This was not sustainable,” he said.

Volner added, “For now, our ability to burn remains an important factor in the survival of HC&S and the 750 jobs and other benefits it provides to Maui residents.”

HC&S produces 150,000 to 200,000 tons of raw sugar and more than 60,000 tons of molasses each year. The company is one of the island’s largest employers, with an estimated annual economic benefit of more than $250 million, including payroll, benefits and vendor purchases.