Zoox grounds Atlanta test fleet after workers report toxic gas exposure symptoms

An OSHA letter to Zoox that TechCrunch viewed said as many as 40 workers may have been exposed to the gases in the vehicles. The Amazon-owned company says the number is lower. TechCrunch spoke with Jay Davis, the contractor who filed the OSHA complaint, as well as one current and two former employees. The other three workers were granted anonymity to discuss private company matters and because they fear retaliation.

Zoox put at least one group of workers back on the road in a different car after one vomited and the rest reported exposure symptoms, a contractor told TechCrunch. That second car may also have contained potentially toxic gases, he said, because the workers experienced another bout of exposure symptoms later that day. “They made us go right back in the field after we said we were throwing up,” Davis told TechCrunch. “I emailed HR, told her what’s going on, and I told her I feel like it’s messed up that y’all made us go [back out].”

Workers reported exposure symptoms and strange smells through much of last month until August 22, when someone called 911 for a sick worker. The facility in northwest Atlanta has operated at limited capacity since then, with the test vehicles quarantined while Zoox investigated the exposures, according to two employees. Zoox’s purpose-built robotaxis, which are all electric, are not affected.

Exactly what gases the Zoox employees were exposed to remains unclear. Davis said he and two other workers who became sick were told at the emergency room that their symptoms were consistent with carbon monoxide exposure. The complaint filed with OSHA mentions possible carbon dioxide, or CO2, exposure.

Zoox told OSHA in a September 10 letter, viewed by TechCrunch, that it examined its test vehicles for signs of CO2 and replaced their 12-volt batteries. Damaged batteries can produce hydrogen sulfide gas, which creates a “rotten egg” smell. Some of the employees who spoke to TechCrunch said they noticed a similar smell in the cars.

Zoox identified 28 employees who rode in six test vehicles that had an “unexplained odor,” the company said in its letter to OSHA. Zoox told OSHA that 10 workers “voluntarily underwent medical evaluation” to “determine whether any exposure had occurred.” Zoox said in the letter that it received only “one medical report identifying CO2 exposure.”

Zoox told TechCrunch it has not identified the presence of carbon monoxide, which is odorless, in its vehicles. The company told TechCrunch it consulted an outside medical expert to help investigate the issues and that the only gas it detected in the impacted vehicles was CO2. In the letter to OSHA, the company said it will add CO2 monitors to the vehicles. OSHA has since closed its inquiry.

“The safety and well-being of our Zoox test fleet operators is our primary concern in this situation,” the company told TechCrunch. “We are taking ongoing, appropriate, and cautious actions to investigate the reported events as necessary and support any needs from our operators. While we investigate these reports thoroughly, we have ceased operations of our test vehicles in this market.”

Cars produce carbon monoxide and carbon dioxide when they burn fuel. These gases can enter a vehicle if there is a leak in the exhaust system; they can also build up if a vehicle runs inside an enclosed space for an extended period. It is a common enough problem that the National Highway Traffic Safety Administration investigated Ford for six years over reports of carbon monoxide buildup in its Explorer SUVs.

In its letter to OSHA, Zoox said it tested the vehicles’ exhaust systems for leaks and performed a “smoke test” for cabin intrusions. It did not say whether it found any evidence of either. The company also removed all the 12-volt batteries, inspected them for damage, and replaced them. It did not tell OSHA whether it found evidence of damage to the batteries. The company keeps its test vehicles running through much of a given day, in part to maintain sensor calibration and reduce the onboard self-driving computer’s boot time.

The illnesses come as Zoox branches into new cities and expands its existing operations in places like Las Vegas and San Francisco, in a bid to catch market leader Waymo. This rapid growth has put some safety monitors at risk. As TechCrunch previously reported, contractors have sustained injuries from sudden braking and swerving in the Zoox test vehicles. Waymo has also reported similar test driver injuries to OSHA.