It is one of the most iconic moments in 80s cinema history.

But behind the audience’s laughter as the giant Stay Puft Marshmallow Man explodes, coating New York City in white fluff, lay a literal LIVING NIGHTMARE for the cast.

Unearthed behind-the-scenes secrets of the 1984 blockbuster Ghostbusters have revealed the “heavy price” paid by actor William Atherton (who played the universally loathed EPA inspector Walter Peck).

Forget computer-generated imagery (CGI). The substance dumped on their heads wasn’t pixels, and it certainly wasn’t sweet marshmallow. It was hundreds of pounds of chemical-laden shaving cream.

[IMAGE: Walter Peck completely covered in white foam] Caption: The hilarious moment of “karma” on screen was actually physical agony for actor William Atherton.

NOT MARSHMALLOW, BUT MENTHOL SHAVING FOAM!

Back in 1984, director Ivan Reitman couldn’t rely on computers to detonate a 100-foot marshmallow monster.

Instead, the production crew raided local supermarkets. According to set reports, approximately 50 gallons of Barbasol shaving cream were mixed with fabric softener to create the sticky, gooey consistency.

However, the real victim of this explosion wasn’t the four Ghostbusters—it was the villain, Walter Peck.

Reitman ordered 75 pounds of the foam to be dumped directly onto William Atherton’s head from a great height to create the most realistic “drenched” effect possible. But onset rumors suggest the actual amount was closer to hundreds of pounds of the heavy mixture.

[IMAGE: Crew members dumping massive buckets of foam from above] Caption: There was no escape. The actors had to just stand there and take the “rain” of heavy foam.

“IT FELT LIKE WET CONCRETE AND BURNED THE SKIN”

In rare interviews, Atherton has recalled the terrifying experience. He revealed that the sheer mass of the foam was so heavy it instantly knocked him to the ground.

“It’s not light like cotton wool,” a source close to the production revealed. “When wet, that amount of foam weighs as much as wet concrete. William was literally crushed.”

To make matters worse, the shaving cream used contained Menthol.

Imagine smearing strong mint toothpaste over your entire body, including your eyes and nostrils. The actors had to endure chemical skin burns for hours under the hot studio lights while waiting to be hosed down.

[IMAGE: Bill Murray and Dan Aykroyd laughing on set, covered in foam] Caption: The main cast got hit too, but “enemy” Walter Peck took the brunt of the abuse. Note Bill Murray’s pained smile.

A DIRECTOR’S PRANK?

Hollywood lore suggests the crew intentionally dumped double the amount on Atherton because his character was… simply so detestable.

In the film, Walter Peck is the bureaucratic nightmare trying to shut down the Ghostbusters. It seems that to satisfy the audience’s rage (and the crew’s), they turned him into a giant human sundae.

Legend Bill Murray (Peter Venkman) once joked: “We hated Walter Peck, so we made sure he was the cleanest man in New York with all that shaving cream.”

Next time you rewatch Ghostbusters, don’t just laugh. Spare a thought for William Atherton’s skin and eyes!