Mysterious flaky white material falls on midtown Manhattan: What is it?

Anyone have a guess what this mysterious flaky material that fell from the sky in midtown Friday is?

For hours on Friday, these snow-like “things” drifted around and collected in piles around 35th Street and Eighth Avenue, even getting on people’s clothes.

One amNewYork staffer reported seeing it even in New Jersey. Another staffer reported that it felt like styrofoam.

Frankly, we’re stumped. A Department of Sanitation spokesman directed us to the city Department of Environmental Protection, which didn’t get back to us by press time.

Hmm, what could it be? The byproduct of a construction site? Was something incinerated? Is Charlie Sheen in town?!