"Allowable levels" refers to the acceptable or permissible amounts or standards set for something. It indicates the maximum or minimum limit within which something can be considered acceptable or within the norm. Full definition
The defeat devices cause the vehicles to emit «much higher» than allowable levels of nitrogen oxide pollution, according to the suit. (automobilemag.com)
From the 2007 Bali Climate Declaration by Scientists, there is pretty good consensus over the maximum allowable level of carbon in the atmosphere and the 50 % reduction in absolute emission levels that needs to be achieved to get there. (sciencebasedtargets.org)
At a Wednesday news conference announcing the move, DOH Commissioner Howard Zucker repeatedly said his agency would start with a safety baseline of 400 ppt safety measure, the EPA's maximum allowable level for short - term PFOA exposure, as it began its health assessment of the contamination. (timesunion.com)