---
kind: "section"
citation: "40 C.F.R. § 61.111"
title: "40"
number: "61.111"
heading: "Definitions."
url: "https://uscodex.org/cfr/40/61.111"
---

# §61.111. Definitions.


As used in this subpart, all terms not defined herein shall have the meaning given them in the Act, in [subpart A of part 61](/cfr/40/part61-subpartA.md), or in [subpart V of part 61](/cfr/40/part61-subpartV.md), and the following terms shall have the specific meanings given them:

In benzene service means that a piece of equipment either contains or contacts a fluid (Liquid or gas) that is at least 10 percent benzene by weight as determined according to the provisions of [§ 61.245(d)](/cfr/40/61.245.md?p=d). The provisions of [§ 61.245(d)](/cfr/40/61.245.md?p=d) also specify how to determine that a piece of equipment is not in benzene service.

Semiannual means a 6-month period; the first semiannual period concludes on the last day of the last month during the 180 days following initial startup for new sources; and the first semiannual period concludes on the last day of the last full month during the 180 days after June 6, 1984 for existing sources.


## Notes

### Source

Source: 49 FR 23513, June 6, 1984, unless otherwise noted.

### Authority

Authority: 42 U.S.C. 7401 et seq.

### Source

Source: 38 FR 8826, Apr. 6, 1973, unless otherwise noted.