The Poncho Z EV, previously due out from Hino by the end of March, is built with hexavalent chromium, according to sources familiar with the matter.
Hino said last week that it was abandoning plans to release the 30-seat bus for the Japanese market.
BYD had planned to supply the Poncho Z EV to Hino under an original equipment manufacturer contract. Originally set for a spring 2022 release, the bus was first delayed to the end of fiscal 2022 over quality issues, Hino said at the time.
Hino had been negotiating with BYD to build the bus without using the chemical but could not reach a resolution.
“EV buses for the Japanese market meet all required laws and standards,” BYD’s Japan unit told Nikkei. When asked about the use of hexavalent chromium, the company declined to comment.
The company sells four types of electric buses in Japan, including the J6, on which the Hino model was based. The revelation has prompted some bus operators to change their plans.
Although no laws in Japan prohibit the use of the substance, it is on a list of substances voluntarily banned by the Japan Automobile Manufacturers Association.
Hexavalent chromium was once widely used in automotive parts and elsewhere in manufacturing for its corrosion resistance and other properties. But it is considered very toxic and a harmful carcinogen.
The substance has not been used in new cars sold in Japan since JAMA banned its use in 2008. The European Union prohibits its use in passenger cars. Hino is a JAMA member but BYD is not.
The Japan Automobile Importers Association ensures that cars imported from automakers in Europe, the US and South Korea do not use hexavalent chromium. When it was found in motorcycles produced abroad and sold by a Japanese auto company in 2017, it resulted in a recall of parts.
Japanese bus companies are taking action.
Saitama Prefecture company Seibu Bus cancelled a Wednesday press event to announce the introduction of BYD electric buses. It was planning to use them for routes in Tokyo and Saitama from this coming Monday. The company said it will “look into the matter”. This would have marked the first time that Seibu Bus operated BYD vehicles.
Kyoto-based Keihan Bus, which purchased four BYD electric buses, said it is considering the next step. Iyotetsu Bus, an Ehime prefecture operator that had planned to introduce the Poncho Z EV, said: “We are considering purchasing a different EV bus in fiscal 2023.”
BYD’s electric buses had been gaining popularity in Japan, with 80 already in use, according to its Japan unit. The company’s share of the Japanese electric-bus market is 70% or so.