Fortron Industries has planned a two-week shutdown beginning in late September for work at its Wilmington facility, including a measure to address a potential source of odor emissions, company officials said Wednesday.

The Wilmington plant at 4600 U.S. Hwy 421 N. manufactures Fortron polyphenylene sulfide, a type of thermoplastic polymer used in automotive, consumer goods, industrial, medical and aerospace applications. In March the N.C. Department of Environmental Quality's Division of Air Quality (DAQ) issued a "Determination of Objectionable Odor" to Fortron.

The odor determination is an investigation tied to compliance with Fortron's permit, said Sharon Martin, a spokeswoman for the state agency. The company, however, is not up for a permit renewal, she added.

According to the March 8 letter, DAQ's Wilmington regional office has responded to complaints about a "catty" odor association with emissions from the plant's operations. The letter stated that in 2018, the office received 25 complaints related to the smell, and another 23 complaints have been filed so far this year.

A determination of maximum feasible controls, outlined in a rule that sets out procedures to address controlling odorous emissions, is due from Fortron to DAQ by Sept. 4, Martin said.

Forton has not yet submitted that, she said.

"We believe that the pressure release valves, on the equipment for safety purposes, may be a potential source of the odor emissions. During the shutdown we will be replacing those valves with the best available control technology," Travis Jacobsen, director of global corporate communications for Fortron and Celanese Crop., said in an email Wednesday.

Fortron Industries is a joint venture between Celanese and Kureha Chemicals Industry Co. of Japan. It started operating at the Wilmington site in 1993.

The work will be part of a planned, routine shutdown, Jacobsen said.

Other work will also take place during the shutdown, which is slated for the last week in September and the first week of October, he said.

The planned work "includes equipment upgrades, equipment inspections, preventive maintenance and annual testing of safety systems," Jacobsen said. "During the shutdown we are upgrading key pressure relief devices on our process and storage tanks to reduce process emissions coming from the facility. In order to do this the production lines have to be shut down."

There will be no reductions in staff while the shutdown takes place, he said.

Most of the plant's employees “will work overtime during this high activity period,” Jacobsen said. “In fact, we expect that during the outage we will also need additional contractor resources to handle the additional workload."

State DAQ officials said the smell is associated with acetone and mesityl oxide emissions from Fortron's operations that react with reduced sulfur compounds to form the aroma compound MMP.

“Historically, people have smelled that offensive odor downtown. That has been happening for years, and people have complained about it,” said Rep. Deb Butler (D-New Hanover), who has been following the issue.

Earlier this year representatives with Fortron visited Butler.

“They brought representatives all the way from New York and Washington to meet with me at my Raleigh office, which I was very impressed ... that they took such an aggressive stance on it, to come and visit with me ... and to detail for me what their plans were for getting ahead of this obnoxious odor," she said.

Butler said she contacted the company just a couple of days ago after the odor was again noticeable in the area and knowing there was an order out by state regulators. Recently, she posted a response from the company on Facebook about the upcoming work.

“I'm very pleased with those developments because I think it shows good faith on their part," Butler said. "We'll just see if it works."