APEX, N.C. — About half of Apex was included in an evacuation last week because officials feared a fire at a hazardous-waste handler had released a cloud of toxic chlorine gas over the town. But a company executive said Monday there was no chlorine gas at the site.

Scott Maris, vice president of regulatory affairs for EQ Industrial Services, said no chlorine gas was stored at the Investment Boulevard plant, and no air samples taken by state monitors at the plant and around Apex have shown any elevated levels of chlorine in the air.

"We don't know precisely what happened," Maris said. "We run a safe operation, but we have had an unfortunate accident."

About 17,000 Apex residents were ordered to leave their homes late Thursday and early Friday because officials feared chemical contamination from a fire at the EQ plant. All residents were allowed to return home by late Saturday.

Officials still are unsure about the cause of the fire. Representatives of the federal Chemical Safety Board said they likely would be in Apex until the end of this week investigating the incident, but they probably wouldn't issue a report for several months.

Maris said the plant stores paints, oils, thinners, antifreeze, detergents and cleaners. He said some of the cleaning products or pool chemicals might have contained chlorine bleach, but he said he doesn't have the chemistry background to know whether bleach could release chlorine gas if ignited.

"Once the investigation is done, there won't be any evidence of wrongdoing," he said, adding that the company plans to rebuild on the site.

Apex Town Manager Bruce Radford said he still wants to obtain a written list of the products inside the EQ facility at the time of the fire so he can get the word out to all local residents.

Two dozen workers were at the EQ North Carolina plant site Monday morning, and trucks moved in and out of the site, clearing away the debris and ensuring no contaminated water seeped from the site.

Maris said the site should be cleaned by next week. An open-air chemical storage building was the only structure involved in the fire, he said, noting EQ's local offices were untouched.

The storage building had no fire suppression system nor 24-hour security, he said. The facility was built before EQ acquired the Apex site, and regulations at that time didn't require either fire suppression or security, he said.

Investment Boulevard, where the building was located, remained blocked off Monday, although nearby businesses were allowed to reopen and bring in their employees and customers.

"I was wondering if we were actually supposed to be here -- police on both ends of the street, lines you have to cross," one man said. "You have to come in and escort them through to show you're a business in this area."

Tests conducted by state environmental officials and by EQ have shown no contamination in the air or in nearby lakes and streams.

But some business owners said they aren't taking any chances.

Jean Sciacca, who owns Apex Gymnastics next door to the EQ plant, hired an independent testing company to check for lead, mercury or other chemical contamination and brought in a cleaning crew to scrub down her gym.

"I just want to make sure the gym is safe for all the children and the parents feel safe in coming back," Sciacca said.

EQ has received about 800 calls to its toll-free assistance line, Maris said. Many people were just seeking more information, he said, but the company plans reimburse Apex residents who can document hotel, meal and incidental expenses incurred because of the evacuation.