I think there is a safety concern, in being able to use materials or products, etc. Knowledge of one of the official languages is key, just for that purpose alone. I know a lot of examples of entire crews speaking Portuguese on the site, and they seem to get along well enough, but I think a lot of the concern about being able to speak one of the official languages on a construction site has to do with safety requirements.
On September 25th, 2017. See this statement in context.