Quote:
	
		
		
			Use masks made with a non-woven, melt-blown polypropylene layer. Don't use masks with holes or a valve, as you will breathe out the virus if you have COVID-19. The main value of wearing a mask is to protect other people.
			
		
	
 and:
	Quote:
	
		
		
			The main value of wearing a mask is to protect other people. If used correctly, masks may prevent sick people from infecting others. 
If you are unknowingly infected, wearing a mask will reduce the chance that you pass COVID-19 on to others. 
Even if you are wearing a mask, stay 1.5 metres away from others, if possible.
			
		
	
 It seems quite clear which way around it is. Masks are worn to prevent the wearer from spreading disease rather than getting disease.