PHILADELPHIA (CBS) – If you smell a strong odor of rotting cabbage throughout the city this week, you’re not losing your mind. Officials say the shuttered Philadelphia Energy Solutions refinery is scheduled to start removing supplies of Mercaptan beginning Monday.

Mercaptan is a colorless gas with a distinctively putrid smell. Some describe the scent as rotting cabbage, smelly socks or rotten eggs.

But don’t worry, Mercaptan is not hazardous.

The work is expected to continue over the next few days and is expected to last about nine days.

If you believe you have a gas leak, please call 9-1-1.

The PES refinery permanently shut down after a massive explosion and fire in June 2019. The 150-year-old site was the largest oil refinery on the East Coast and had been processing 335,000 barrels of crude oil daily into gasoline, jet fuel, propane, home heating oil and other products.