### Question
What is the definition of startup?


### Answer
The definition of **startup** is as follows in *40 CFR § 52.01*:

> the setting in operation of a source for any purpose.

#### Citation:
  - *40 CFR § 52.01*
  - Heading: **PART 52—APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS > Subpart A—General Provisions > SUBCHAPTER C—AIR PROGRAMS (CONTINUED) > SUBCHAPTER C—AIR PROGRAMS (CONTINUED)**

