MAC-EQS (Maximum Allowable Concentration EQS)

A single-reading concentration limit that must never be exceeded at any monitoring point — protects against acute pollution peaks.

Maximum Allowable Concentration Environmental Quality Standard. Unlike the AA-EQS, this is not averaged — a single measurement that exceeds the MAC-EQS constitutes a breach. Designed to protect against acute (short-term) toxic effects. Where the MAC-EQS is listed as 'na' (not applicable), the AA-EQS alone provides sufficient protection. Where listed as 'nd' (not derived), insufficient toxicological data exists to set a value — the AA-EQS applies only.

Legal reference

Directive 2008/105/EC Art 4, as amended by Directive (EU) 2026/805