Site Feedback

Website Feedback

This contact form is only for website help or website suggestions. If you have questions or comments regarding a published document please contact the publishing agency. Comments or questions about document content can not be answered by OFR staff. Please do not provide confidential information or personal data.

Title 40

Displaying title 40, up to date as of 7/08/2026. Title 40 was last amended 7/08/2026.
view historical versions
  1. Title 40 —Protection of Environment
  2. Chapter I —Environmental Protection Agency
  3. Subchapter C —Air Programs
  4. Part 63 —National Emission Standards for Hazardous Air Pollutants for Source Categories
  5. Subpart IIIII   View Full Text
  • Details
  • Print
  • Search
  • Subscribe
  • Timeline
  • Go to Date
  • Published Edition
  • Developer Tools
eCFR Content

The Code of Federal Regulations (CFR) is the official legal print publication containing the codification of the general and permanent rules published in the Federal Register by the departments and agencies of the Federal Government. The Electronic Code of Federal Regulations (eCFR) is a continuously updated online version of the CFR. It is not an official legal edition of the CFR.

Learn more about the eCFR, its status, and the editorial process.

Title 40Protection of EnvironmentPart / Section
Chapter IEnvironmental Protection Agency1 – 1099
Subchapter CAir Programs50 – 99
Part 63National Emission Standards for Hazardous Air Pollutants for Source Categories63.1 – 63.12099
Subpart IIIIINational Emission Standards for Hazardous Air Pollutants for Mercury Cell Chlor-Alkali Plants63.8180 – 63.8266
What This Subpart Covers63.8180 – 63.8186
§ 63.8180What is the purpose of this subpart?
§ 63.8182Am I subject to this subpart?
§ 63.8184What parts of my plant does this subpart cover?
§ 63.8186When do I have to comply with this subpart?
Emission Limitations and Work Practice Standards63.8190 – 63.8192
§ 63.8190What emission limitations must I meet?
§ 63.8192What work practice standards must I meet?
Operation and Maintenance Requirements63.8222 – 63.8226
§ 63.8222What are my operation and maintenance requirements?
§ 63.8226What are my general requirements for complying with this subpart?
Initial Compliance Requirements63.8230 – 63.8236
§ 63.8230By what date must I conduct performance tests or other initial compliance demonstrations?
§ 63.8232What test methods and other procedures must I use to demonstrate initial compliance with the emission limits?
§ 63.8234What equations and procedures must I use for the initial compliance demonstration?
§ 63.8236How do I demonstrate initial compliance with the emission limitations and work practice standards?
Continuous Compliance Requirements63.8240 – 63.8248
§ 63.8240What are my monitoring requirements?
§ 63.8242What are the installation, operation, and maintenance requirements for my continuous mercury monitoring systems?
§ 63.8243What equations and procedures must I use to demonstrate continuous compliance?
§ 63.8244How do I monitor and collect data to demonstrate continuous compliance?
§ 63.8246How do I demonstrate continuous compliance with the emission limitations and work practice standards?
§ 63.8248What other requirements must I meet?
Notification, Reports, and Records63.8252 – 63.8258
§ 63.8252What notifications must I submit and when?
§ 63.8254What reports must I submit and when?
§ 63.8256What records must I keep?
§ 63.8258In what form and how long must I keep my records?
Other Requirements and Information63.8262 – 63.8266
§ 63.8262What parts of the General Provisions apply to me?
§ 63.8264Who implements and enforces this subpart?
§ 63.8266What definitions apply to this subpart?
Table 1 to Subpart IIIII of Part 63
Work Practice Standards—Design, Operation, and Maintenance Requirements
Table 2 to Subpart IIIII of Part 63
Work Practice Standards—Required Inspections
Table 3 to Subpart IIIII of Part 63
Work Practice Standards—Required Actions for Liquid Mercury Spills and Accumulations and Hydrogen and Mercury Vapor Leaks
Table 4 to Subpart IIIII of Part 63
Work Practice Standards—Requirements for Mercury Liquid Collection
Table 5 to Subpart IIIII of Part 63
Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans
Table 6 to Subpart IIIII of Part 63
Examples of Techniques for Equipment Problem Identification, Leak Detection and Mercury Vapor
Table 7 to Subpart IIIII of Part 63
Required Elements of Washdown Plans
Table 8 to Subpart IIIII of Part 63
Requirements for Cell Room Monitoring Program
Table 9 to Subpart IIIII of Part 63
Required Records for Work Practice Standards
Table 10 to Subpart IIIII of Part 63
Applicability of General Provisions to Subpart IIIII
eCFR Content