The presence of a “biohazard” onboard a United Airlines flight in the United States forced the plane to divert as passengers and crew started to vomit. 

On Sunday at about 9.30am local time, Flight UA2477 departed from Houston’s George Bush Intercontinental Airport and headed for Boston. But it had to divert to Washington DC for a “deep clean” after a passenger became ill onboard, the New York Post reported. 

The American newspaper shared an audio recording, initially posted to social media platform X, in which a staff member described the severity of the situation to air traffic control. “I talked to the crew and it sounds like it’s quite bad back there. The crew is vomiting, and passengers all around are asking for masks,” said a man on the recording. 

He added: “With this kind of being a biohazard, I think we need to get this plane on the ground asap”. 

The aircraft, a Boeing 737-800, carried 155 passengers and six crew members - though despite the drama, none of them needed medical care once they deplaned at Washington’s Dulles International Airport. 

In a statement to the New York Post, United Airlines said: “The aircraft is currently undergoing a deep clean and we are working to get customers on their way to Boston soon”. 

A biohazard incident usually refers to being exposed to a biological substance, such as vomit or faeces, which could be bad for a person’s health. 

Last year, another biohazard event forced Delta Airways to divert just an hour and a half into a flight from Georgia in the US to Barcelona in Spain. 

“We’ve had a passenger who’s had diarrhoea all the way through the airplane, so they want us to come back to Atlanta,” the captain of the A350 was recorded saying. 

One passenger took to social media to express disgust: “It was pretty bad,” they wrote on Reddit. “It [had] dribbled down the aisle, [and] smelled horrible.” 

Passengers spent the entirety of the eight hours and 13 minutes in the same plane, with lingering smells.