What is leaded gasoline?
Leaded gasoline is more commonly known as petrol; it is a liquid derived from petroleum. Its distinguishable feature is the chemical element it contains as additive known as tetraethyl lead. So, basically, leaded gasoline is normal gasoline (petrol) with the additive tetraethyl lead.
With time, as evidence of its negative impacts on the environment was generated, it has been banned in a number of countries, including the US. It was commercialized back in the 1920s, when higher compression engines were developed; this type of fuel is an octane booster allowing for engine compression and the combination would lead to enhanced vehicle performance; hence why leaded gasoline was popularized at the beginning.
The purpose of additives
Increasing octane levels implies adding hydrocarbon mixed with benzene. These hydrocarbon fuels would then be released as greenhouse gases, accounting to global warming. Additives came in handy to decrease the carbon accumulating in internal engines. They would also enhance the process of combustion that releases energy, and pave the way for easier ignition in conditions of cold temperatures. By adding the lead compound, pre-ignition or detonation was avoided; the problem known as engine-knocking that is said to damage engines was thus prevented.
Furthermore, the additives allowed for better lubrication of the inside and valves of the engine, thus providing greater protection to the valve seats.
The additives led to environmental issues
However, with time, questions were raised as to the relevance of the additives by environmentalists who argued that the leaded gasoline was not compatible with the catalytic converters that are meant to filter the waste gases coming from exhaust pipes of vehicles. The lead compound was found to be hindering the task of the catalytic converters; both would interact to produce further unwanted chemicals that were being emitted into the environment.
Condemning the use of leaded gasoline
Therefore, the Environmental Protection Agency (EPA) shifted to denouncing the use of leaded gasoline. Health professionals also joined the ride after correlating the level of consumption of lead products with the amount of lead being detected in the human bloodstream: leaded gasoline was determined to be a factor causing a dangerous health problem known as lead poisoning in people; the condition is associated with unpleasant effects such as neurological damage, gastrointestinal discomfort, and cognitive impairment.
Therefore, with time, leaded gasoline has been replaced by healthier – or at least, less unhealthy – alternatives. For instance, other additives were used, such as aromatic hydrocarbons, ethers, and alcohols like methanol and ethanol.