A Lower East Side handyman says he got ill when a ceiling full of rats collapsed on him, raining down rodents and feces, because his bosses skimped on safety gear — and to make matters worse he got fired for filing a workplace-safety complaint, according to a new lawsuit.

Robert Petersen, 45, of Exact Builders Group LLC says he had been tasked with installing a new wall at a West 147th Street building on Aug. 20 that involved cleaning up rat droppings — so he asked for goggles, gloves and a special mask, his Manhattan Supreme Court lawsuit says.

But his boss Crystal Fernandez told him “Don’t be a baby, just get it done … do what you need to do,” before sending him to store that didn’t have Occupational Safety and Health Administration-approved gear, according to the suit.

“She made it sound like either do the work or I was going to get fired,” Petersen, of the Lower East Side, told The Post.

“I was cleaning up rat feces and rat urine on soaked pieces of insulation. There were dead rats and there were [live rats] running all around me. They were trying to come out when I was trying to plaster it.”

After spending some 16 hours doing the filthy work over two days, he was called to another job to repair a leaking hole in a ceiling, he said.

Again, despite it being infested with the critters he wasn’t given proper gear — and this time he had to put his head into the hole to see inside the ceiling and “the rats were running around my head,” Petersen said.

Then while Petersen was pulling down the wet boards in the ceiling, “the whole thing came down on me — rats, feces, you name it,” he said. “You cringe. I don’t like rats, mice, I don’t like any kind of rodents. I was disgusted. You feel grossed out. You are itching and scratching.”

He developed itchy welts on his arms and face, began vomiting, and was eventually forced to miss a week of work and check himself into the hospital on Aug. 22 — at which point Fernandez threatened to fire him, the court papers say.

Petersen filed a complaint with OSHA over the unhygienic conditions, the court papers say.

After returning to work Sept. 3, he was given a task above his pay grade, and so he asked for a written order, which Fernandez refused to give him, the court documents claim.

Petersen was fired on Sept. 13 and was only told that it was “not going to work out,” the court papers say.

“Upon information and belief, Mr. Petersen’s termination was in direct retaliation for disclosing the Defendant’s violations to OSHA, the DOH [Department of Health] and the DOL [Department of Labor],” the court documents charge.

A lawyer for Exact Builders, Idan Sims, declined to comment.

Fernandez could not be reached for comment.