40 CFR § 261.199 - Special requirements for incompatible materials.

---
identifier: "/us/cfr/t40/s261.199"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 261.199 - Special requirements for incompatible materials."
title_number: 40
title_name: "Protection of Environment"
section_number: "261.199"
section_name: "Special requirements for incompatible materials."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "I"
subchapter_name: "SOLID WASTES"
part_number: "261"
part_name: "IDENTIFICATION AND LISTING OF HAZARDOUS WASTE"
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. 6905, 6912(a), 6921, 6922, 6924(y) and 6938."
regulatory_source: "45 FR 33119, May 19, 1980, unless otherwise noted."
cfr_part: "261"
---


# 261.199 Special requirements for incompatible materials.

(a) Incompatible materials must not be placed in the same tank system.

(b) Hazardous secondary material must not be placed in a tank system that has not been decontaminated and that previously held an incompatible material.