Protecting and Securing Chemical Facilities from Terrorist Attacks Act of 2019 This bill reauthorizes the Department of Homeland Security's (DHS) Chemical Facility Anti-Terrorism Standards (CFATS) program until May 1, 2025. The CFATS program requires chemical facilities to assess and address their threat vulnerabilities. The bill requires DHS to (1) verify information submitted by a covered chemical facility prior to assigning such facility a lower risk tier or determining that it no longer presents a high level of security risk, and (2) develop a voluntary program for chemical facilities to address potential security risks. DHS shall, among other things (1) provide for an annual review of a facility's compliance with its emergency response plan; (2) make necessary information available to state, local, and regional fusion centers and state and local government officials to ensure that emergency response providers are prepared; (3) establish a Chemical Security Advisory Committee to advise DHS on the implementation of this bill; and (4) study how to improve training and support for local emergency response providers in areas with high concentrations of covered facilities in how to respond to a terrorist attack on a chemical facility. The Cybersecurity and Infrastructure Security Agency shall (1) conduct a review of potential effects of attacks on covered chemical facilities or other critical infrastructure, and (2) establish a secure communications and information technology infrastructure or platform that allows facility owners and operators to voluntarily report on emerging threats. The Government Accountability Office shall evaluate the effectiveness of DHS risk-based performance standards.