Tetraethyllead

tetraethyllead [¦te·tre¦eth·əl′led]

(organic chemistry)

Pb(C₂H₅)₄A highly toxic lead compound that, when added in small proportions to gasoline, increases the fuel's antiknock quality. Abbreviated TEL.

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Tetraethyllead 

(or TEL), (C₂H₅)₄Pb, a colorless, oily, volatile liquid with a density of 1.65 g/cm³ and a boiling point of 195°C (with decomposition). TEL is produced by the reaction of ethyl chloride, C₂H₅C1, and a lead-sodium alloy, PbNa (about 10 percent Na). It is widely used as a component of lead tetraethyl solution that is used as an antiknock additive for motor fuels for carburetor internal-combustion engines.

TEL is toxic. Poisoning by TEL is possible during the manufacture of TEL and lead tetraethyl solution, during the transport or storage of lead tetraethyl solution and ethylated gasoline, and during the operation or servicing of internal-combustion engines. TEL enters the body through the respiratory tract, uninjured skin, or the gastrointestinal tract and is excreted with the urine and feces. It accumulates in parenchymatous organs, such as the liver and kidneys, and in the brain.

In acute TEL poisoning, there is a latent period lasting a few hours to several days. The first indications of poisoning are severe headache, weakness, and euphoria. Sleep is interrupted by nightmares. Characteristic of TEL poisoning are disorders of the autonomic nervous system, such as a drop in blood pressure and body temperature, a slowing of the pulse, and an increase in salivation. Difficulty in walking, impairment of memory, and emotional instability are also possible. Chronic poisoning remains latent for a long period of time. Symptoms of mild cases are asthenia and disorders of the autonomic nervous system; severe cases are manifested by toxic psychoses. Development of encephalopathy and the decline of mental powers are also possible.

Treatment for acute TEL poisoning involves gastric lavage and the administration of soporifics, sedatives, and cardiovascular agents; for chronic cases, general restorative treatment is also indicated. Preventive measures include compliance with health regulations governing technological processes and facilities, observance of the rules of personal hygiene, use of protective clothing and remote control, finishing of rooms with materials that do not absorb TEL and are easily cleaned, and periodic medical examinations for workers.

REFERENCES

Motornye i reaktivnye masía i zhidkosti. Edited by K. K. Papok. Moscow [1964].
Ermakov, E. V. Khronicheskoe otravlenie tetraetilsvintsom. Leningrad, 1963.
Drogichina, E. A. Professional’nye bolezni nervnoi sistemy. Leningrad, 1968.

A. A. KASPAROV and V. V. PANOV