China is reportedly considering regulations for mandatory in-car air quality to protect the health of drivers.

This could increase the costs for automakers importing vehicles from markets without such rules, sources with knowledge of the matter told Reuters.

New in-car air quality regulations in the world’s biggest auto market will likely be unsettling for auto interior parts suppliers too as they will need to tweak their products to meet new requirements, the sources said.

According to talks led by officials from the environment watchdog, new vehicles will be required to clear an in-car environment test after their doors have been shut for hours.

Regulators will test the level of contaminants including formaldehyde and benzene, three people familiar with the matter said on condition of anonymity as the talks are not yet public.

Officials also want to test electromagnetic radiation levels as electric vehicles and combustion-engine cars use more electronic devices, the sources said.

Some customers have expressed concern about radiation from these electronic devices, but an official at China Association of Automobile Manufacturers said last year that such radiation would not harm human health.

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China’s Ministry of Ecology and Environment did not immediately respond to a request for comment.

China currently allows global brands to sell cars without local certification for in-car air quality standards.

In 2011, China’s environment and quality watchdogs published a guideline for passenger vehicle’s in-air quality but stated the standards were just recommended and not compulsory.

However, in recent years, China has been trying to enforce its own vehicle certification standards.

In 2019, it accelerated an independently designed strict emissions standard for gasoline cars after using European-like emissions rules for years, leading to a sales chaos.