40 CFR §63.5835

1. (a)You must be in compliance at all times with the work practice standards in Table 4 to this subpart, as well as the organic HAP emissions limits in Tables 3, or 5, or the organic HAP content limits in Table 7 to this subpart, as applicable, that you are meeting without the use of add-on controls.
2. (b)You must be in compliance with all organic HAP emissions limits in this subpart that you meet using add-on controls at all times.
3. (c)You must always operate and maintain your affected source, including air pollution control and monitoring equipment, according to the provisions in § 63.6(e)(1)(i).