- A 30-foot furnace's door at Tesla's Austin factory was stuck open for months, The Wall Street Journal reported.
- Ex-employees said the fault allowed pollutants to escape and raised the temperature as high as 100 degrees.
- Elon Musk's companies have recently come under growing scrutiny over environmental violations.
Workers at Tesla's Austin factory were said to have faced temperatures as high as 100 degrees Fahrenheit and a "constant haze" because the door of a 30-foot furnace would not close properly, The Wall Street Journal reported Sunday night.
Unnamed former employees at the Texas plant told the newspaper that the door was faulty for months while Elon Musk's automaker ramped up production of the Model Y SUV in 2022.
In a memo sent to the Environmental Protection Agency this year and viewed by the Journal, a whistleblower said Tesla used an "elaborate ruse" to conceal the issue from regulators.
The memo reportedly said Tesla adjusted the amount of fuel going into the furnace, which melts aluminum used to make car parts, and temporarily closed the door.
The tactic appeared to help Tesla pass emissions tests carried out by the Texas Commission on Environmental Quality, according to the memo seen by the Journal.
Tesla did not respond to a request for comment from the outlet and did not immediately respond to one from Business Insider.
It's not the first time Elon Musk's companies have faced scrutiny for their environmental impact.
SpaceX was fined almost $150,000 in September for dumping wastewater into wetlands near its Texas launch site in 2022. Tesla paid $1.5 million in February to settle a lawsuit accusing it of mishandling hazardous waste at its factories in California.
In its Sunday report, the Journal mentioned findings that Tesla had also dumped wastewater filled with toxins from its Austin plant into the local sewage system.
Staff who raised warnings about environmental violations at the Austin plant were ignored and feared they could be fired, former workers told The Journal.
One worker reportedly said in the memo sent to the EPA that Tesla had "repeatedly asked me to lie to the government" so the company could operate without paying for proper environmental controls.