40 CFR § 725.428 - Requirements for the Tier II exemption.

---
identifier: "/us/cfr/t40/s725.428"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 725.428 - Requirements for the Tier II exemption."
title_number: 40
title_name: "Protection of Environment"
section_number: "725.428"
section_name: "Requirements for the Tier II exemption."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "R"
subchapter_name: "TOXIC SUBSTANCES CONTROL ACT"
part_number: "725"
part_name: "REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "15 U.S.C. 2604, 2607, 2613, and 2625."
regulatory_source: "62 FR 17932, Apr. 11, 1997, unless otherwise noted."
cfr_part: "725"
---


# 725.428 Requirements for the Tier II exemption.

The manufacturer or importer of a new microorganism for commercial purposes may submit to EPA a Tier II exemption request in lieu of a MCAN under subpart D of this part if all of the following conditions are met:

(a) The recipient microorganism is listed in and meets any requirements specified in § 725.420.

(b) The introduced genetic material meets the criteria under § 725.421.

(c) Adequate physical containment and control technologies are used. The criteria listed under § 725.422 for physical containment and control technologies of facilities should be used as guidance to satisfy the Tier II exemption request data requirements listed at § 725.455(d). EPA will review proposed process and containment procedures as part of the submission for a Tier II exemption under this section.