For NGOs: Projects must consider health and work safety regulations (laws on Occupational Health and Safety (OSHA), or in German:
Arbeitsschutzgesetz). You must follow any safety rules that the festival has created – that is particularly important in cases of emergency – even if you are an activist group trying to stir up the establishment. Pay attention to what the security team says at the venue and act accordingly. If the festival offers you to participate in tours of the area, please participate – it's for your own and your team’s safety (it also gives you an inside view into the festival people don't usually get :)).
If you have concerns or feel unsafe, you can talk to the security staff. Some festivals have additional awareness teams who are trained to deal with serious issues like sexual assault. Treat the festival crew and your fellow festival goers with respect.
For festivals: Make sure you treat the NGO teams as crew, i.e. keep them in the loop, so they get informed in cases of emergency (e.g., evacuation because of severe weather).
Find out more about health and safety laws in the EU:
https://osha.europa.eu/enCheck out this panel from the German conference Future of Festivals on health and safety regulations at festivals with Parookaville (German with German subtitles):