The Clean Air Act 1956 (4 & 5 Eliz. 2. c. 52) was a law passed by the Parliament of the United Kingdom. It was created mainly to address the Great Smog of 1952 in London. The law was supported by the Ministry of Housing and Local Government in England and the Department of Health for Scotland. It remained in effect until 1993.

The law introduced several steps to reduce air pollution. A major step was requiring the use of smokeless fuels, especially in areas with large populations called "smoke control areas." This helped reduce smoke and sulfur dioxide from household fires. The law also included rules to lower the release of gases, grit, and dust from chimneys and smokestacks.

The law was an important step in creating a legal system to protect the environment. Later laws, such as the Clean Air Act 1968, made changes to it. The entire law was replaced by the Clean Air Act 1993.

Background

London was known for its thick, foggy air, often called "pea soup fog." In 1880, meteorologist Rollo Russell wrote an important pamphlet titled London Fogs, stating that "many deaths occur each year due to smoke-fogs, which can make lung diseases worse."

Over time, London passed several laws to improve air quality, such as the Smoke Abatement, London Act of 1853 and the Public Health (London) Act of 1891. However, even though people understood the connection between air pollution and health by the late 1800s, these efforts did not successfully reduce health problems.

In December 1952, a severe smog, called the "Great Smog," covered London. The effects were extreme: over 4,000 people died shortly after the smog began, causing public worry. The fog was so thick that trains, cars, and public events had to stop. An additional 8,000 people died in the weeks and months that followed. Today, it is believed that about 12,000 people died due to the smog.

This event showed that pollution was a serious and deadly problem. The smog’s impact marked an important moment in the modern environmental movement.

The government formed a committee led by civil engineer Sir Hugh Beaver to study air pollution in London. The committee’s 1954 report discussed the social and economic costs of air pollution and stated that clean air was as important as clean water had been in the mid-1800s. It suggested replacing domestic coal with coke and using other "smokeless" fuels like electricity and gas. However, industries that produced these fuels, such as coke and gas plants and power stations, still burned coal to create them. For example, in the late 1800s, six million tons of coal in North-East England were converted to coke, releasing about two million tons of harmful substances like carbonic and sulfuric acid. This meant pollution was not being reduced but moved from where it was used to where it was produced.

The electricity industry used a lot of coal and contributed to air pollution. The Beaver committee used the example of the newly built Bankside power station in London to recommend that all new urban power stations install flue-gas desulphurisation. It claimed this method would be practical and cost-effective if it added no more than 0.06 d. to 0.07 d. to the cost of one unit of electricity (1 kWh).

The British Electricity Authority doubted the benefits of desulphurisation and challenged the committee’s recommendations. It argued that the proposal "would harm the economy of electricity development in this country" and that the financial costs "could be more serious than any previous restrictions." The Authority claimed installing scrubbers in all power stations would cost £10 million annually and increase electricity costs by 0.1 d. per kWh, exceeding the cost-effectiveness standard proposed in the Beaver report. It also criticized the committee for not properly evaluating the economic trade-offs of different pollution-reduction methods. The Authority stated that burning coal in modern power stations with efficient pollution-control equipment and tall chimneys was "an extremely efficient way to manage pollution in terms of cost."

Legislation

The government at first did not want to act quickly and tried to make the problem seem smaller because of economic challenges. It took actions by some members of Parliament, including Conservative member Gerald Nabarro, who supported a Private Member's Bill about controlling coal burning at home, to convince the government to change the law. The Clean Air Act continued efforts to control pollution, especially in London, where air quality had been poor for a long time.

The Clean Air Act of 1956 included several steps to reduce air pollution. It allowed the creation of "smoke control areas" in towns and cities where only smokeless fuels could be burned. By encouraging homes to use cleaner fuels like electricity and gas instead of coal, the Act reduced smoke and sulfur dioxide from household fires. It also required that dark smoke from chimneys be prevented, new furnaces to be smokeless, local planning groups to ensure buildings had taller and more effective chimneys, and that grit and dust from emissions be reduced. These changes changed how private homes were allowed to act, influencing discussions about government rules, public health, and the limits of government control.

The smog in 1952 pushed for stronger action. In addition to the Clean Air Act, it led to the City of London (Various Powers) Act of 1954 and later the Clean Air Act of 1968.

Section 35(1) of the Act canceled 12 previous laws, which are listed in the fourth schedule of the Act.

Air pollution and its health effects remained a problem in London. During the London fog from December 2–5, 1957, smoke and sulfur dioxide levels reached levels similar to 1952, causing 760–1,000 deaths. Another event in 1962 caused 750 deaths.

Further legislation

The 1956 law was updated by the Clean Air Act of 1968 (c. 62). This law made it illegal to release dark smoke from chimneys. It also allowed the government official to set limits on how much grit and dust could be released from furnaces. The law required new furnaces to have equipment to capture pollution and set rules for the height and placement of chimneys. It also let the government official create areas where smoke control was required and limit the use of fuels not approved for those areas.

The 1956 and 1968 Clean Air Acts were replaced by new laws that updated and expanded the rules from earlier. The 1993 Act grouped these rules into six sections:

• Dark smoke
• Smoke, grit, dust, and fumes
• Smoke control areas
• Control of other types of air pollution
• Information about air pollution
• Special cases, including: how the law relates to the Environmental Protection Act 1990, colliery spoilbanks, railway engines, and other transportation.