safety valve

noun [C]

Definition

› PRODUCTION a part of a machine that opens to release pressure if it becomes too high: The process involves shutting safety valves beneath the water's surface to prevent oil and gas releases.

› something in a system or situation that helps when problems become too great: Experts say there must be a safety valve built into the system to relieve the stress caused by an economic slowdown. There's no safety valve, like higher air fare prices, to offset higher oil prices.

(Definition of safety valve noun from the Cambridge Business English Dictionary © Cambridge University Press)