40 CFR § 60.681 - Definitions.

---
identifier: "/us/cfr/t40/s60.681"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 60.681 - Definitions."
title_number: 40
title_name: "Protection of Environment"
section_number: "60.681"
section_name: "Definitions."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "C"
subchapter_name: "AIR PROGRAMS"
part_number: "60"
part_name: "STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES"
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"
regulatory_source: "36 FR 24877, Dec. 23, 1971, unless otherwise noted."
cfr_part: "60"
---


# 60.681 Definitions.

As used in this subpart, all terms not defined herein shall have the meaning given them in the Act and in subpart A of this part.

*Glass pull rate* means the mass of molten glass utilized in the manufacture of wool fiberglass insulation at a single manufacturing line in a specified time period.

*Manufacturing line* means the manufacturing equipment comprising the forming section, where molten glass is fiberized and a fiberglass mat is formed; the curing section, where the binder resin in the mat is thermally “set;” and the cooling section, where the mat is cooled.

*Rotary spin* means a process used to produce wool fiberglass insulation by forcing molten glass through numerous small orifices in the side wall of a spinner to form continuous glass fibers that are then broken into discrete lengths by high velocity air flow.

*Wool fiberglass insulation* means a thermal insulation material composed of glass fibers and made from glass produced or melted at the same facility where the manufacturing line is located.