40 CFR § 373.4 - Definitions.

---
identifier: "/us/cfr/t40/s373.4"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 373.4 - Definitions."
title_number: 40
title_name: "Protection of Environment"
section_number: "373.4"
section_name: "Definitions."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "J"
subchapter_name: "SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS"
part_number: "373"
part_name: "REPORTING HAZARDOUS SUBSTANCE ACTIVITY WHEN SELLING OR TRANSFERRING FEDERAL REAL PROPERTY"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 9620."
regulatory_source: "55 FR 14212, Apr. 16, 1990, unless otherwise noted."
cfr_part: "373"
---


# 373.4 Definitions.

For the purposes of implementing this regulation, the following definitions apply:

(a) *Hazardous substances* means that group of substances defined as hazardous under CERCLA 101(14), and that appear at 40 CFR 302.4.

(b) *Storage* means the holding of hazardous substances for a temporary period, at the end of which the hazardous substance is either used, neutralized, disposed of, or stored elsewhere.

(c) *Release* is defined as specified by CERCLA 101(22).

(d) *Disposal* means the discharge, deposit, injection, dumping, spilling, leaking or placing of any hazardous substance into or on any land or water so that such hazardous substance or any constituent thereof may enter the environment or be emitted into the air or discharged into any waters, including groundwater.