KNIGHTDALE -- Raleigh's fire marshal said Monday that a hazardous material team could not pinpoint the irritating substance that sent six people to the hospital and sickened about two dozen more at a McDonald's restaurant in Knightdale over the weekend.
Fire Marshal Rusty Styons said the culprit may have been pepper spray or ammonia that someone either accidentally or intentionally released into the fast food restaurant's ventilation system late Sunday morning; it would have circulated throughout the restaurant.
"There was the suggestion that a chemical repellent had been released in the bathroom," Styons said.
Eastern Wake Emergency Medical Services was among the emergency responders sent to the McDonald's restaurant at 7141 Knightdale Blvd. shortly after 10 a.m. Sunday. More than 30 customers and employees were evacuated, complaining of burning sensations in their noses and eyes.
Thirty-one people, including customers and employees, were treated by emergency medical personnel, said Jeffrey Hammerstein, district chief for Wake County EMS.
There were additional complaints of persistent coughing, throat irritation, dizziness and general fatigue, Styons said.
Most of the six people who were hospitalized were taken to WakeMed's Raleigh campus, said Eddie Ross, Eastern Wake's operations chief.
"It appeared to be airborne," Ross said about the stinging substance. "I don't think it was anything in the food."
An off-duty Knightdale Public Safety firefighter was in the restaurant at the time of the incident. The firefighter gave a 911 dispatcher information about what was happening at the restaurant, Styons said.
The Raleigh hazmat team investigated several potential causes. The team measured the chlorine levels of powdered bleach that's used to clean the restaurant.
It also looked at ammonia and refrigerants. "They determined that those products were not improperly handled," Styons said.
Styons said the hazmat team's effort to investigate the irritant was thwarted, because whatever had been released in the restaurant had dissipated by the time the team arrived.
The store managers are reviewing security surveillance video to determine whether the incident needs to be turned over to the police for criminal investigation.
Attempts to reach Knightdale Police Chief Shawn Brown were unsuccessful Monday.
