WINDSOR, ONT. -- The Municipality of Chatham-Kent has declared a second state of emergency after confirming hydrogen sulfide is once again present in the building on 15 Erie St. North in Wheatley.

Acting CAO Cathy Hoffman says, “It is different with this situation with a very strong odour of hydrogen sulphide that is also outside of the building and in the surrounding areas to the original source.”

The source of the gas remains unknown, but emergency crews are collecting samples, and tests results will allow officials to plan for next steps.

“Those samples right now have been sent to a couple of different labs. We’re waiting for results back from them -- we expect to come in the next 24-48 hours,” Hoffman says.

Officials say 23 homes and 13 businesses have been evacuated, leaving 52 people displaced since Monday, and providing accommodation for a longer period could be a challenge.

Hoffman explains it's because, “...it is the time of year when we have many people that join our communities in both Chatham-Kent and Essex County to participate in farming, harvesting, etc.”

She adds they are working with impacted business owners to try to mitigate losses.

“To be able to get some of their product and save some of that which might otherwise be lost if left there over a number of days given the fact that hydro has been shut off in those areas.”

Hydrogen sulfide is a naturally occurring gas that is both toxic and flammable.

A previous state of emergency was issued on June 2 after a reported gas leak at the same Erie Street address.

Everything returned to normal by the end of the month, when no more leaks were detected.

Emergency crews remain on scene monitoring the situation. The municipality is asking provincial officials for help.

- With files from CTV News Windsor's Angelo Aversa