Zoox grounds Atlanta fleet after toxic gas exposure reports

Zoox has grounded its autonomous vehicle test fleet in Atlanta after safety drivers were potentially exposed to carbon monoxide, carbon dioxide, or hydrogen sulfide gas inside its vehicles last month, TechCrunch has learned. The repeated incidents led one worker to file a complaint with the Occupational Safety and Health Administration, which opened an inquiry and told Zoox to investigate; OSHA has since closed that inquiry.

As many as 40 workers were possibly exposed to the gases, according to a letter from OSHA to Zoox, though the Amazon-owned company says the actual number is lower. At least one group of workers was put back on the road in a different car after one vomited and the rest reported exposure symptoms; that second car may have also contained potentially toxic gases, since the workers experienced another round of exposure symptoms later the same day. “They made us go right back in the field after we said we were throwing up,” Jay Davis, one of the contractors who got sick in mid-August, told TechCrunch.

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

In a September 10 letter to OSHA, Zoox said it examined its test vehicles for signs of CO2 and replaced their 12-volt batteries, which can produce hydrogen sulfide gas — a “rotten egg” smell some workers said they noticed — if damaged. After publication, Zoox told TechCrunch it has since detected no damage to the batteries and no signs of hydrogen sulfide gas. The company identified 28 employees who rode in six test vehicles with an “unexplained odor,” and said 10 of them voluntarily underwent medical evaluation, of which only one report identified CO2 exposure. Zoox said it hasn’t identified the presence of carbon monoxide, which is odorless, and will add CO2 monitors capable of also detecting carbon monoxide and hydrogen sulfide.

Zoox is an outlier among major robotaxi developers because its test fleet uses internal-combustion Toyota Highlander SUVs, while Waymo, Tesla, Avride, and Motional all use electric vehicles that don’t produce exhaust gases; May Mobility’s fleet includes some hybrid vans, and Nvidia uses a small number of gas and electric sedans. The illnesses come as Zoox expands into new cities and existing markets like Las Vegas and San Francisco in a bid to catch market leader Waymo — rapid growth that has already put some safety monitors at risk, with contractors previously sustaining injuries from sudden braking and swerving in Zoox test vehicles, and Waymo reporting similar test-driver injuries to OSHA.

Zoox told TechCrunch that the safety and well-being of its test fleet operators is its primary concern in this situation, and that it is taking what it called ongoing, appropriate, and cautious action to investigate the reported exposures and support its operators, while it has ceased operating test vehicles in that market during the investigation.

Why it matters

The incident adds Zoox to a string of robotaxi developers facing safety scrutiny as the industry races to expand test fleets faster than it can always account for the risks to the human safety monitors still riding along.