Nontoxic Transformer Oil

Water Wonk Wednesdays

A weekly column on science, policy, and innovations.


By Erik Baard

A Con Ed transformer burst in a Dumbo, Brooklyn electrical substation, releasing about 37,000 gallons of insulating oil. A significant amount of oil made its way underground into the East River, upon which it was carried as far north as Gantry Plaza State Park.

Con Ed uses dielectric fluid, a toxic synthetic mineral oil. The utility has the option of using natural and synthetic esters and pentaerythritol, which are common transformer fluid upgrades now for coastal applications because they are nontoxic and biodegradable. They also have a higher flash point (a safety bonus atop the environmental advantages) and other superior qualities for daily functioning. Another option under development is using vegetable oils, but the load demands and weather extremes of NYC so far preclude that option. Nanotech enhancements might make coconut or other natural oils more suitable in the future. Many of these products are already marketed.

Other substitutes for mineral oil , like silicone and fluorocarbons, are safer and superior within the transformer, but a hazard to the environment if released.

After the transformer explosions we witnessed during Hurricane Sandy, perhaps it’s time to explore more modern transformer fluid.

Furure accidents needn’t result in a threat to the environment and paddlers. HarborLAB volunteers provide paddling programs at Gantry to hundreds of children. Paddlers were restricted this week from entering a wide zone.

HarborLAB contributed to the safety response by reporting the sheen at Gantry to the NY State Department of Environmental Conservation’s Spill Hotline:

NYS Spill Hotline: 1-800-457-7362
National Response Center: 1-800-424-8802






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