'Working environment' may be the easy answer, but as this so-called Danglish term is used in e.g. Directive 2013/35/EU, it may be more EUnglish than Danglish.
EN: 'Under the Treaty, the European Parliament and the Council may, by means of directives, adopt minimum requirements for the encouragement of improvements, in particular of the working environment, to guarantee a better level of protection of the health and safety of workers.'
DA: 'I henhold til traktaten kan Europa-Parlamentet og Rådet ved udstedelse af direktiver vedtage minimumsforskrifter med henblik på forbedring af især arbejdsmiljøet for at sikre et højere niveau for beskyttelse af arbejdstagernes sikkerhed og sundhed.'
On the other hand, in Regulation (EC) No 1338/2008, 'arbejdsmiljø' is the Danish translation of 'health and safety at work'.
Some research in each case, for example at
https://eur-lex.europa.eu/advanced-search-form.html?locale=d... would be a good idea. The bilingual view is a great help.
'Working environment' may not be a common expression in UK employment law, but in this case, we're talking about the Danish implementation of EU law, so an accepted English EU term would seem quite acceptable.