On the night of 3 December 1984, the city of Bhopal in Madhya Pradesh witnessed the uncontrolled release of methyl isocyanate gas from the Union Carbide chemical plant, a facility located in the midst of densely populated residential areas. Within minutes, streets, houses and entire neighbourhoods were engulfed in a toxic cloud, creating scenes of devastation unmatched in the history of industrial disasters. The placement of the plant, embedded deep within the residential fabric of the city, had for years concealed profound weaknesses in local zoning practices, urban master planning and the regulation of industrial siting. By the morning of 3 December, it became evident that no buffer zones had been allocated, no wind-direction studies undertaken, no assessment of population density or industrial hazards conducted, and no emergency routes planned for the plant or the neighbourhoods around it.

The tragedy forced governments, courts, environmental experts and urban planners to confront the fact that the distance between heavy industry and residential settlements can never remain a mere administrative formality; it is a fundamental requirement for the preservation of human life. Across India, an urgent national debate emerged over which provisions had permitted such a hazardous facility to operate within a residential zone and why the master plan had failed to enforce a clear separation between industrial and residential land use. These questions became the basis for the most significant legislative reforms in India’s urban and industrial history. Two years later, the Environment Protection Act of 1986 granted the central government authority to determine the siting of industrial units, enforce buffer zones and restrict hazardous industries from operating near homes, schools, markets or hospitals. It established, for the first time, the principle that industrial location must correspond to the degree of risk associated with each facility.

Following this, the Hazardous Chemicals Rules of 1989 were promulgated, requiring every industrial plant to prepare detailed risk maps, maintain minimum distances from residential populations, account for wind direction, groundwater flows, fire safety pathways and potential patterns of toxic dispersion. The rules also made the creation of green belts around industrial areas mandatory in order to slow or prevent the spread of toxic emissions in the event of an accident. In the years that followed, the very concept of urban master planning changed, introducing risk-based zoning into Indian planning practice and dividing urban space into clearly defined zones such as safe residential sectors, mixed-use areas, general industrial districts and hazardous industrial exclusion zones. After 3 December, it was further established that the denser a city’s population, the stricter the prohibition on hazardous industry within its bounds, and that industrial licensing must be accompanied by insurance, safety audits, risk maps and emergency response plans. The Public Liability Insurance Act of 1991 subsequently required every hazardous facility to demonstrate its capacity to provide immediate compensation in the event of an accident, drawing industrial construction, location and permitting firmly into the domain of real estate regulation.

The Bhopal disaster permanently altered India’s understanding of urban space; cities were no longer viewed as mere collections of roads, buildings and lanes, but as environments where every plan, every factory and every decision concerning land must place human safety at its core. 3 December 1984 became a defining reminder that poor zoning is not a technical lapse but a determinant of life and death, forming the foundation of modern land-use regulation, industrial oversight and urban safety laws in India.

The magnitude of the tragedy and its status as one of the most catastrophic events in human industrial history led filmmakers in India and abroad to document it from several angles. Among these, the best-known is the 2014 international film Bhopal: A Prayer for Rain, which reconstructs the events preceding the disaster, highlighting the safety failures and operational conditions inside the plant. Earlier, in 1999, the Indian film Bhopal Express depicted the tragedy through the experience of an ordinary family caught unawares by the sudden release of toxic gas. In 2004, the BBC produced One Night in Bhopal, a detailed documentary examining the technical causes of the incident, the breakdown of industrial oversight and the impact of the disaster on the urban landscape. Additional documentaries, including Bhopal: A Search for Justice, explored the long-term health effects, legal battles and continuing contamination affecting the community. The human scale of suffering, combined with failures in urban planning and industrial zoning, made the disaster a subject of global cinematic and documentary attention, preserved through serious artistic, investigative and historical filmmaking.