Chlorine is one of the world’s most widely used chemicals, particularly in Iran. The gas is primarily used for drinking water disinfection, wastewater treatment, industrial chemical production, and in the pharmaceutical and food industries . Despite its diverse applications, chlorine is also an extremely dangerous, toxic, and corrosive substance; leaks or improper use can cause serious injuries and environmental damage. Therefore, Iran and many other countries have enacted strict laws and regulations
governing the production, transportation, storage, and use of chlorine . These laws and regulations serve to protect public health and minimize environmental and industrial risks.
The role of chlorine in Iranian industry
In Iran, chlorine is mainly used in the following industries:
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Treatment of urban and rural water (disinfection of drinking water pipes)
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Wastewater treatment plants
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Paper mills and pulp and paper plants
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Petrochemical industry and oil refining industry
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Chemical products such as PVC and solvents are manufactured there.
Although there are many alternatives to chlorine , such as ozone and chlorine dioxide (ClO₂), chlorine remains the most important component for water disinfection due to its low cost and high effectiveness.
The dangers of chlorine and the need for legal restrictions
Chlorine is classified as an extremely dangerous chemical and is listed in international lists of controlled substances (e.g., the Chemical Weapons Convention ) . Hazards associated with chlorine include:
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Health effects: Inhaling chlorine gas can cause respiratory irritation, severe coughing and breathing difficulties; high concentrations can be fatal.
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Environmental impacts: Chlorine leaks can kill plants, pollute surface waters, and kill aquatic life.
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Industrial hazards: Explosions of chlorine cylinders or leaks in processing plants can lead to major accidents (similar incidents occurred in Iran).
These risks have led to the development of specific regulations to control chlorine throughout its entire life cycle, from production to consumption.
Legal basis for the use of chlorine gas in Iran
1. National laws
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Under the Hazardous Substances Administration Act (enacted by the Environmental Protection Agency and the U.S. Department of Health and Human Services),
chlorine is a controlled substance and classified as a hazardous chemical. Its manufacture, transportation, and use require government permits. -
Occupational health and safety regulations in the chlorine industry (cooperatives, Ministry of Labour and Social Protection):
Employers must provide protective equipment such as masks and ventilation systems and conduct training for employees. -
Dangerous goods transport regulations (Ministry of Roads and Urban Development):
Liquid or gaseous chlorine must be transported in standard tank trucks, in special steel cylinders and with a special transport permit. -
Environmental Protection and Improvement Act:
Industrial plants that use chlorine gas must install and monitor leakage control systems.
2. Supervisory authority
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Environmental Protection Department → Monitoring of Environmental Impacts
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Ministry of Health → Monitoring of public health and drinking water safety
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Ministry of Energy → Regulates the use of chlorine in wastewater treatment plants
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American National Standards Organization (ANSI ) → Development of technical specifications for chlorine storage cylinders and tanks.
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Ministry of Labor → Monitoring of workplace safety and protection of workers
There are certain restrictions on the use of chlorine.
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Production and import
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Chlorine may only be produced or imported by companies that have a corresponding license from the Ministry of Industry and Environment.
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The import of chlorine is subject to customs control and requires a special permit.
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storage
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The cylinder must be made of corrosion-resistant materials and comply with ISO standards.
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Chlorine storage facilities must be equipped with ventilation systems, leak detectors and special fire extinguishing systems.
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Translations
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The transport of chlorine gas on city streets is prohibited and requires the approval of the traffic police.
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Tank trucks used to transport petroleum products must be marked as dangerous goods and equipped with safety equipment.
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Used for water purification.
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The US Department of Energy recommends a free chlorine level in drinking water between 0.2 and 0.8 mg/L.
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Excessive use is prohibited and will be punished with fines.
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Waste and wastewater
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Industrial plants must neutralize residual chlorine in wastewater before releasing it into the environment.
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Legal alternatives to chlorine
Given the high risks, many Iranian oil refineries have begun to gradually switch to alternative energy sources.
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Ozone (O₃): has a better disinfecting effect than chlorine, but its production costs are high.
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Chlorine dioxide (ClO₂): high disinfection effect with few side effects.
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Ultraviolet (UV) radiation: used for disinfecting drinking water in small towns.
In some provinces, the use of these methods is mandatory or recommended.
Consequences of rule violations
Companies or organizations that do not comply with the regulations on chlorine use must expect the following consequences:
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In accordance with the regulations of the Environmental Protection Agency and the Ministry of Health, a fine will be imposed.
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In the event of a leak or large-scale contamination, the industrial plant must be shut down.
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Criminal liability of managers for accidents resulting in bodily injury or death
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Exclusion from the granting of new licenses in the industrial or service sector
Problems and difficulties with implementation in Iran
Despite the clarity of the rules, their full implementation continues to encounter difficulties:
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Some small wastewater treatment plants lack the necessary safety and monitoring equipment.
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Unsafe transport of chlorine on rural roads and paths
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Use of worn and non-standard cylinders
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There is a lack of training for staff on methods for eliminating chlorine leaks.
The future of Iranian chlorine laws
Given the global trend towards reducing chlorine consumption and switching to sustainable technologies, it is expected that:
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Legal regulations are being tightened (especially in the transport and storage sector).
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Alternatives to chlorine must be developed , and their use should gradually become mandatory.
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Expansion of the use of intelligent monitoring systems (using digital sensors and SCADA systems) to control chlorine leaks in Iran.
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Iranian legislation should be more closely aligned with international standards.
In conclusion
Chlorine remains one of the most important chemicals in Iran, but its use is strictly restricted by law due to the high risks involved . Iranian regulations governing the production, transport, storage, and use of chlorine primarily focus on public safety, environmental protection, and occupational safety . Nevertheless, its use presents challenges and potential hazards. In the future, Iran will gradually reduce its reliance on chlorine and replace it with safer technologies.