The Netherlands Authority for Consumers and Markets (ACM) is starting an investigation into misleading sustainability claims in the energy, dairy and clothing sector.

The organization has asked a total of 170 companies to check their claims for correctness.

ACM has opted for these three sectors because in those sectors sustainability plays an important role for consumers in purchasing and because it saw many potentially misleading claims during preliminary investigation.

"We want to activate companies to critically examine their claims for accuracy, clarity and substantiation. Consumers must be able to trust the sustainability claims. And companies with honest claims must not face unfair competition from companies that mislead consumers," says Edwin van Houten, director of Consumers at the ACM.

The authority does not list company names, but does provide some examples of misleading claims it found.

She wrote to sixty companies in the energy sector about claims such as "the majority of our green electricity is generated in the Netherlands", while the label shows that this is only 20 percent.

Seventy companies in the clothing sector received a letter.

For example, a clothing provider said that a T-shirt he sold was made of organic cotton, but it actually consisted of only 50 percent organic cotton.

Finally, 40 companies are being investigated in the dairy sector.

For example, a milk carton said "30 percent less CO2 emissions".

ACM found that unclear and asked for more explanation.

Ultimately, it turned out to be 30 percent less CO2 emissions from the production of the packaging than from previous packaging.

If companies continue to mislead consumers about their products, ACM can impose fines.

These can amount to 900,000 euros per violation or a percentage of the turnover.

The organization will publish the results in mid-June.