The Hazardous Organic NESHAP (HON) Rule requires chemical manufacturing facilities to implement fenceline monitoring programs to ensure hazardous air pollutants remain below EPA action levels. With compliance deadlines beginning in July 2026, facilities must monitor six regulated hazardous air pollutants (HAPs), respond quickly to exceedances, maintain detailed records, and conduct quarterly reporting. This document outlines the regulatory requirements and explains how real-time monitoring and automated workflows can replace delayed passive methods with faster, more defensible compliance.