40 CFR § 75.42 - Reliability criteria.

---
identifier: "/us/cfr/t40/s75.42"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 75.42 - Reliability criteria."
title_number: 40
title_name: "Protection of Environment"
section_number: "75.42"
section_name: "Reliability criteria."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "C"
subchapter_name: "AIR PROGRAMS"
part_number: "75"
part_name: "CONTINUOUS EMISSION MONITORING"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 7401-7671q and 7651k note."
regulatory_source: "58 FR 3701, Jan. 11, 1993, unless otherwise noted."
cfr_part: "75"
---


# 75.42 Reliability criteria.

To demonstrate reliability equal to or better than the continuous emission monitoring system, the owner or operator shall demonstrate that the alternative monitoring system is capable of providing valid 1-hr averages for 95.0 percent or more of unit operating hours over a 1-yr period and that the system meets the applicable requirements of appendix B of this part.