You may not have heard of sulfur hexafluoride also known as SF6, but its one of the most potent greenhouse gases. Last year, a metal recycling company in Anderson emitted more of it than any other industrial facility in the country.

TCE is used in cleaning products, degreasers, brake cleaners and tire repair sealants. The EPA said exposure to the chemical has been known to cause cancer as well as harm the brain and reproductive system and there are many safer alternatives available.

The fire at the former plastics recycling business in April displaced more than 1,000 people and sent harmful smoke and debris into the air.

Its been about seven years since the Environmental Protection Agency found a chemical used to sterilize medical equipment and spices was a lot more harmful than the agency originally thought. But the agency still hasnt finalized a rule limiting the chemical at commercial sterilizers like Cook Group Inc. in Ellettsville.

Utilities, industries and state regulators are all concerned about a proposed federal rule to nearly eliminate carbon emissions at power plants. It was one of many topics at a legislative summer study committee last week.

Most of the decline comes from coal plants closing. Power plants in Indiana contribute more than half of all greenhouse gas emissions in the state; a quarter comes from steelmakers like U.S. Steel and Cleveland Cliffs.

Both advocates and the Environmental Protection Agency have raised environmental justice concerns about the plant's location.

The U.S. Supreme Court ruled in favor of Indiana and 18 other states in a case to limit how the federal government can reduce greenhouse gas emissions.

The site of the old Cities Service Refinery now houses a CITGO oil storage facility and vacant property owned by Oxy USA. The EPA found groundwater in the center of the site had high levels of fuel chemicals like benzene, which can cause blood cancers.

Among other things, the EPA wants to treat groundwater south of the Amphenol site using a barrier to break down harmful chemicals as they flow through.