Outrage as it emerges carmakers Volkswagen, BMW and Daimler deliberately tested exhaust fumes on humans

Fresh controversy has erupted over exhaust testing by some German car makers. Photo / AP

German carmakers are engulfed in a new scandal after it emerged they had tested potentially dangerous exhaust fumes on humans.

A research group set up by Volkswagen, BMW and Daimler, the maker of Mercedes, deliberately exposed human test subjects to toxic exhaust chemicals for hours at a time in an attempt to prove they were not carcinogenic between 2012 and 2015.

Details of the human testing were exposed only days after it emerged that the carmakers had carried out similar tests on monkeys.

The revelations sent shockwaves through the German establishment.

Barbara Hendricks, the German environment minister, described the experiments as "abominable".

"These tests on monkey and humans cannot be justified ethically in any way," a spokesman for Angela Merkel said.

"The outrage felt by many people is completely understandable."

In the human testing, 19 men and six women were exposed to different concentrations of nitrogen oxides for several hours at a time, according to details released in the German press.

They were then checked in hospital for harmful effects.

Nitrogen oxides are toxic chemicals found in diesel exhaust fumes, and the carmakers reportedly wanted to counter a World Health Organisation decision to classify them as carcinogenic.

The results of the tests, which were carried out in the western German city of Aachen, have not been released, but one of the scientists involved said Monday they were of "limited value" as the findings would not apply to the general population and nitrogen oxides are not the only harmful chemicals in diesel exhaust.

The testing was carried out by the European Research Association for Environment and Health in the Transport Sector (EUGT), a research group set up and funded by the three carmakers which was shut down in 2017.

The same group was responsible for a similar 2014 test in the US in which 10 monkeys were exposed to diesel fumes for several hours, details of which emerged over the weekend.

The controversy comes as the German car industry tries to recover from the Dieselgate scandal of 2015, in which it emerged several carmakers had fitted software to their diesel engines designed to cheat emissions tests.

Car manufacturers were yesterday scrambling to condemn the tests and contain the damage.

Daimler announced a "comprehensive investigation".

"We expressly distance ourselves from the studies and the EUGT," it said in a statement.

"We are appalled by the extent of the studies and their implementation. We condemn the experiments in the strongest terms."

VW apologised for the tests on monkeys.

"Volkswagen Group explicitly distances itself from all forms of animal cruelty," it said in a statement.

"Animal testing contradicts our own ethical standards."

Stephan Weil, the regional prime minister of Lower Saxony state, which is a maor shareholder in VW, condemned the tests as "absurd and disgusting".

"Lobbying is no excuse for such testing," he said, adding that he would demand VW conduct an urgent review of the matter.

Employees at VW reacted angrily to the latest scandal.

"If these reports are true, this had nothing to do with ethical behavior, nothing at all," Bernd Osterloh, the head of the workers' council at the carmaker said.

"If those responsible at the time are still on the board, then personal consequences must be considered."