People might share this on Facebook or Twitter, but if Tesla manages to build a 2nm chip factory, billionaire Elon Musk says he could… eat a grilled cheese sandwich and smoke a cigar right inside the facility.

Elon Musk, CEO of Tesla and SpaceX, recently appeared on the Moonshots podcast, where he criticized the semiconductor industry’s approach to cleanrooms as “wrong.”

He even joked that if Tesla built a 2nm chip factory, he could eat a grilled cheese sandwich and smoke a cigar inside.

“I think they are doing cleanrooms wrong in modern fabs. I’d bet that Tesla will have a 2nm fab, and I could eat a grilled cheese and smoke a cigar right inside it,” Musk said.

When asked if this was his vision of an “ideal” factory, and whether he had devised a solution to protect wafers from contaminants, Musk replied that wafers should be kept in absolute isolation at all times. “Just always isolate the wafers,” he said.

A semiconductor factory is a large industrial complex, tightly integrating multiple spaces and complex systems. At its heart are ultra-clean cleanrooms, where silicon wafers are processed.

Surrounding and beneath are vacuum systems, gas handling, exhaust pipes; technical corridors for equipment maintenance, chemical distribution infrastructure, and waste treatment, along with office areas and control centers for management, engineering, and monitoring tasks.

Essentially, cleanrooms are enclosed spaces within the factory, fully separated from other areas. Their cleanliness is determined by ISO standards, which define the maximum number of particles allowed per cubic meter of air based on particle size.

For example, an ISO Class 1 cleanroom allows a maximum of 10 particles sized 0.1 micrometers or larger per cubic meter; ISO Class 2 allows up to 100 particles of the same size. Critical processes such as extreme ultraviolet (EUV) or deep ultraviolet (DUV) lithography, or advanced transistor gate formation, must be carried out in ISO Class 1 or 2 environments.

ISO Class 3 cleanrooms allow more particles — up to 1,000 per cubic meter. Even so, these spaces are far cleaner than typical manufacturing facilities.

Given these strict standards, eating or smoking inside a cleanroom is absolutely unacceptable. Such actions could generate hundreds of millions or even billions of contaminant particles. In fact, a single human breath produces millions of tiny particles along with moisture, not to mention biological contamination from bacteria or viruses.

Even in an ideal scenario, where wafers and equipment are perfectly isolated, human breath — let alone smoke or food crumbs — can alter the environment, impacting ultra-sensitive EUV mirrors and delicate chemical reactions inside the factory.

Eating and smoking are also strictly restricted outside cleanrooms to ensure safety and prevent contamination. In theory, Elon Musk could enjoy a grilled cheese or smoke a cigar in office areas. However, even ordinary office spaces nearly always ban smoking.

This is not the first time Musk has publicly criticized the chip industry. While he has praised manufacturing partners such as TSMC or Samsung Foundry, the billionaire has not shied away from complaining that chip factories are building too slowly and not expanding capacity fast enough.

It is also not the first time Musk has publicly considered Tesla building its own semiconductor production facility.

However, many analysts consider this plan highly unlikely. Following Musk’s recent remarks, some experts argue that he may not fully understand how modern advanced semiconductor fabs operate — where “cleanliness” is not just a technical guideline, but the lifeblood of the entire industry, according to Tom’s Hardware.