A chemical accident is the unintentional release of one or more hazardous chemicals, which could harm human health and the environment. Such events include fires, explosions, and release of toxic materials that may cause people illness, injury, or disability. Chemical accidents can be caused for example by natural disasters, human error, or deliberate acts for personal gain.^[1] Chemical accidents are generally understood to be industrial-scale ones, often with important offsite consequences. Unintended exposure to chemicals that occur at smaller work sites, as well as in private premises during everyday activities are usually not referred to as chemical accidents.

Process safety is the engineering discipline dealing with chemical accident hazards understanding and management. Process safety's scope extends however to fires and explosions from hazardous materials generally not referred to as 'chemicals', such as refined and unrefined hydrocarbon mixtures.

Chemical accidents are relatively common in the United States, with a significant accident occurring on average multiple times per week. Most chemical accidents never make national headline news. American chemical industry public relations professionals claim that such accidents are becoming less frequent but the U.S. Environmental Protection Agency states that they are increasing in frequency, with higher average annual rates of population evacuations and of people needing medical treatment resulting from chemical accidents. Texas is the leading U.S. state in chemical accidents.^[2]

The most dangerous chemical accident recorded in history was the 1984 Bhopal gas tragedy in India, in which more than 3,000 people died after highly toxic methyl isocyanate was released at a Union Carbide pesticides factory. The release happened after the storage tank safety valve had failed to contain the excess pressure created by the exothermic reaction between water and methyl isocyanate.^[3] The accident was caused by a faulty valve that let the water into the tank.^[3] The safety refrigeration unit for the tank also was not functional since it did not have any coolant.^[3]

The 2020 Beirut explosion was one of the biggest non-nuclear explosions in history.^[4] It happened when approximately 2,750 tons of ammonium nitrate inside a warehouse at the port exploded.^[4]

To keep safe in your workplace you should know the chemicals you use, if you don't know the chemical all work sites are required to have a safety data sheet or SDS, this will list all the chemicals in your workplace and all the information related to them. Along with knowing your chemicals you should know your workplace such as, escape routes, the location of fire extinguishers, eye washers, emergency showers, and the SDS. Practicing good hygiene in your workplace such as properly storing chemicals, cleaning down surfaces, and using proper labels can help prevent accidents. ^[5]

PPE is the final line of defense between you and a chemical accident, so it is important to use proper PPE that fits you and is rated for your particular chemical hazard. However, the best protection at controlling an accident is preventing it from occurring but if an accident does occur it is important to properly report the hazard so it can be fixed in the future.^[5]

In the European Union, incidents such as the Flixborough disaster and the Seveso disaster led to legislation such as the Seveso Directive, which mandates safety reports to be prepared by process and storage plants and issued to local and regional authorities.^[6]

In the United States, concern about chemical accidents after the Bhopal disaster led to the passage of the 1986 Emergency Planning and Community Right-to-Know Act. The EPCRA requires local emergency planning efforts throughout the country, including emergency notifications. The law also requires companies to make publicly available information about their storage of toxic chemicals. Based on such information, citizens can identify the vulnerable zones in which severe toxic releases could cause harm or even in some cases death.

Alongside the EPCRA two other government regulations were formed the Process Safety Managment and the Risk Managment Plans. These agencies help with the control and management of chemical accidents however the differ slightly from each other. PSM focuses on protecting workers and employees that can potentially be exposed and is run by OSHA. The RMP focuses on the outside community and environment and is controlled by the EPA.^[7]

In 1990 the Chemical Safety and Hazard Investigation Board (CSB) was established by the Congress, though it did not become operational until 1998. The Board's mission is to determine the root causes of chemical accidents and issue safety recommendations to prevent future chemical accidents. Note that the CSB does not issue fines or citations since the Congress designed the agency to be non-regulatory.^[8] It also organizes workshops on a number of issues related to preparing for, preventing, and responding to chemical accidents.^[9]

To prevent Chemical Accidents around the Globe the United Nations has put forth many regulatory and precautionary action thru their environmental protection branch. They have put forth the process of CAPP, Chemical Action Prevention and Preparedness. The three main goals of CAPP are to increase countries' understanding of chemical accidents, Increase the capabilities of environmental agencies in other countries, and help countries develop their own CAPP programs.^[10]

The United Kingdom has one agency specializing in chemical exposures the UKHSA, their priority is to identify and strengthen capabilities relating to chemical exposures. The UKHSA has two tools the NSRA, National Security Risk Assessment and the NRR, National Risk Register both these agencies identify chemical hazards and risk which helps inform the UKHSA. ^[11]

• Chemical safety
• Process safety
• Process safety management

• 24-7 Response
• Brandweerinformatiecentrum voor gevaarlijke stoffen/Fire services information centre for dangerous goods (in Dutch)
• OECD Programme on Chemical Accidents: Environment Directorate
  • Guiding Principles for Chemical Accident Prevention, Preparedness and Response
• Preventing Chemical Accidents – How to Prevent Chemicals From Contaminating Your Workplace – Safety Storage Systems
• U.S. Chemical Safety Board