'If you say you're ethical, you have to back it up'
Oatly is a company which makes a range of milks out of oats. Since its products are plant-based, rather than animal-based, it says this makes it an environmentally ethical business. This is a big selling point with millennials, says CEO Toni Petersson.
But, he adds "if you're going to be ethical, you need to back up every claim that you make".
Video Journalist: Jeremy Howell
Find more business tips at CEO Secrets. You can also follow the series on the BBC News app by adding the topic 'CEO Secrets' in My News.