Ammonia, a toxic gas, is used every day by many companies and some use large amounts.
The PublicSource, an in-depth news organization based in Pittsburgh, released a new report that claims 1.5 million Pennsylvanians live near hazardous amounts of ammonia.
It has put together an online database at publicsource.org that lets you find out if there is a facility near you.
The Midstate has had several small ammonia leaks. In 2009, workers at the Verdelli Farms plant in Harrisburg were evacuated after a forklift operator hit an ammonia pipe in a refrigeration system. One worker was treated.
In 2008, an ammonia spill was reported at the Giant Foods Warehouse near Carlisle. Workers were able to contain the leak to one room, and no one was hurt.
If there was a large ammonia leak, it could be deadly.
"It can cause serious burns and if exposed to enough of it, it will asphyxiate you," said Bill Heltzel, senior investigative reporter for PublicSource.
After months of research, the staff at PublicSource has put together an online database which shows you how close you live to what they call "dangerous stockpiles of ammonia" and the worst case scenario if there was a leak.
For example, the site claims if there was a major ammonia leak at the SFI plant in Shippensburg, 12,000 people within 1.7 miles would be affected.
On a larger scale, the Hershey Creamery in Harrisburg could potentially affect 58,000 people.
"The people that live close to this are the ones that need the information the most, and if you do not have this information a lot of people die," said Heltzel. "The first step is awareness, and I think if there are chemicals around you the next step is then to talk to your local officials."