Back Tetraëtiellood Afrikaans رباعي إيثيل الرصاص Arabic تترااتیل قورغوشون AZB Tetraetil olovo BS Tetraetilplom Catalan Tetraethylolovo Czech Tetraetylbly Danish Tetraethylblei German Tetraetilo de plomo Spanish Tetraetüülplii Estonian

Tetraethyllead

Tetraethyllead
Skeletal formula
Ball-and-stick model
Names
Preferred IUPAC name
Tetraethylplumbane
Other names
Lead tetraethyl

Tetraethyl lead

Tetra-ethyl lead
Identifiers
3D model (JSmol)
Abbreviations TEL
3903146
ChEBI
ChemSpider
ECHA InfoCard 100.000.979 Edit this at Wikidata
EC Number
  • 201-075-4
68951
MeSH Tetraethyl+lead
RTECS number
  • TP4550000
UNII
UN number 1649
  • InChI=1S/4C2H5.Pb/c4*1-2;/h4*1H2,2H3; checkY
    Key: MRMOZBOQVYRSEM-UHFFFAOYSA-N checkY
  • CC[Pb](CC)(CC)CC
Properties
C8H20Pb
Molar mass 323.4 g·mol−1
Appearance Colorless liquid
Odor pleasant, sweet[1]
Density 1.653 g cm−3
Melting point −136 °C (−213 °F; 137 K)
Boiling point 84 to 85 °C (183 to 185 °F; 357 to 358 K) 15 mmHg
200 parts per billion (ppb) (20 °C)[1]
Vapor pressure 0.2 mmHg (20 °C)[1]
1.5198
Structure
Tetrahedral
0 D
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Flammable, extremely toxic
GHS labelling:
GHS06: Toxic GHS08: Health hazard GHS09: Environmental hazard
H300+H310+H330, H360, H373, H410
P201, P202, P260, P262, P264, P270, P271, P273, P280, P281, P284, P301+P310, P302+P350, P304+P340, P308+P313, P310, P314, P320, P321, P322, P330, P361, P363, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g. diesel fuelInstability 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g. hydrogen peroxideSpecial hazards (white): no code
4
2
3
Flash point 73 °C (163 °F; 346 K)
Explosive limits 1.8%–?[1]
Lethal dose or concentration (LD, LC):
35 mg/kg (rat, oral)
17 mg/kg (rat, oral)
12.3 mg/kg (rat, oral)[2]
30 mg/kg (rabbit, oral)
24 mg/kg (rat, oral)[2]
850 mg/m3 (rat, 1 hr)[2]
650 mg/m3 (mouse, 7 hr)[2]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 0.075 mg/m3 [skin][1]
REL (Recommended)
 TWA 0.075 mg/m3 [skin][1]
IDLH (Immediate danger)
 40 mg/m3 (as Pb)[1]
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Tetraethyllead (commonly styled tetraethyl lead), abbreviated TEL, is an organolead compound with the formula Pb(C2H5)4. It was widely used as a fuel additive for much of the 20th century, first being mixed with gasoline beginning in the 1920s. This "leaded gasoline" had an increased octane rating that allowed engine compression to be raised substantially and in turn increased vehicle performance and fuel economy.[3][4] TEL was first synthesized by German chemist Carl Jacob Löwig in 1853. American chemical engineer Thomas Midgley Jr., who was working for the U.S. corporation General Motors, was the first to discover its effectiveness as an knock inhibitor on December 9th, 1921, after spending six years attempting to find an additive that was both highly effective and inexpensive.[5]

Of the some 33,000 substances in total screened, lead was found to be the most effective antiknock agent,[6][7] in that it necessitated the smallest concentrations necessary; a treatment of 1 part TEL to 1300 parts gasoline by weight is sufficient to suppress detonation.[8] The four ethyl groups in the compound served to dissolve the active lead atom within the fuel.[9] When injected into the combustion chamber, tetraethyllead decomposed upon heating into ethyl radicals, lead, and lead oxide. The lead oxide scavenges radicals and therefore inhibits a flame from developing until full compression has been achieved, allowing the optimal timing of ignition, as well as the lowering of fuel consumption.[9] Throughout the sixty year period from 1926 to 1985, an estimated 20 trillion liters of leaded gasoline at an average lead concentration of 0.4 g/L were produced and sold in the United States alone, or an equivalent of 8 million tons of inorganic lead,[10] three quarters of which would have been emitted in the form of lead chloride and lead bromide. Estimating a similar amount of lead to have come from other countries' emissions, a total of more than 15 million tonnes of lead may have been released into the atmosphere.[11]

In the mid-20th century, scientists discovered that TEL caused lead poisoning and was highly neurotoxic to the human brain, especially in children.[12] Approximately 90% of the total lead in a human is present in the bones, deposited in the form of insoluble Lead(II) phosphate salt, with a half-life longer than twenty years.[13][14] The United States and many other countries began phasing out the use of TEL in automotive fuel in the 1970s. With EPA guidance and oversight, the US achieved the total elimination of sales of leaded gasoline for on-road vehicles on January 1st, 1996.[15] By the early 2000s, most countries had banned the use of TEL in gasoline. In July 2021, the sale of leaded gasoline for cars was completely phased out worldwide following the termination of production by Algeria, prompting the United Nations Environment Program (UNEP) to declare an "official end" of its use in cars on August 30, 2021.[16]

In 2011, researchers retroactively estimated the annual impact of tetraethyl lead worldwide to be the following: 1.1 million excess deaths, 322 million lost IQ points, 60+ million crimes, and 4% of worldwide GDP (around 2.4 trillion United States dollars per year).[17]

  1. ^ a b c d e f g NIOSH Pocket Guide to Chemical Hazards. "#0601". National Institute for Occupational Safety and Health (NIOSH).
  2. ^ a b c d "Tetraethyl lead". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  3. ^ "Tetra-Ethyl Lead as an Addition to Petrol". British Medical Journal. 1 (3504): 366–7. 3 March 1928. doi:10.1136/bmj.1.3504.366. PMC 2455205. PMID 20773729.
  4. ^ "After Lead?", Popular Science (October 1987 ed.), Bonnier Corporation, p. 94, October 1987, archived from the original on 13 July 2024, retrieved 23 August 2020
  5. ^ Nriagu, Jerome O. (1 March 1990). "The rise and fall of leaded gasoline". Science of the Total Environment. 92: 13–28. Bibcode:1990ScTEn..92...13N. doi:10.1016/0048-9697(90)90318-O. ISSN 0048-9697.
  6. ^ Nriagu, Jerome O. (1 March 1990). "The rise and fall of leaded gasoline". Science of the Total Environment. 92: 13–28. Bibcode:1990ScTEn..92...13N. doi:10.1016/0048-9697(90)90318-O. ISSN 0048-9697.
  7. ^ Seyferth, Dietmar (1 December 2003). "The Rise and Fall of Tetraethyllead. 2". Organometallics. 22 (25): 5157. doi:10.1021/om030621b. ISSN 0276-7333.
  8. ^ Seyferth, Dietmar (1 December 2003). "The Rise and Fall of Tetraethyllead. 2". Organometallics. 22 (25): 5163. doi:10.1021/om030621b. ISSN 0276-7333. After the Ethyl concentrate has been mixed with gasoline (1 part of tetraethyllead to 1300 of gasoline) Midgley said there is no health hazard, provided that it is not misused; nor, he claimed, was there any evidence that the exhaust of a motor using leaded gasoline as fuel was dangerous.
  9. ^ a b Seyferth, Dietmar (1 December 2003). "The Rise and Fall of Tetraethyllead. 2". Organometallics. 22 (25): 5154–5178. doi:10.1021/om030621b. ISSN 0276-7333. For the purpose of this essay it will suffice to say that, in order to be effective, tetraethyllead must under go thermal decomposition in the automobile engine to give ultimately ethyl radicals and gaseous lead atoms. The latter, in the presence of air, are oxidized to lead monoxide. This, either in gaseous form or as a fog of fine particles, is believed to inactivate intermediates of the hydrocarbon oxidation, perhaps alkyl hydro-peroxides, thus inhibiting the chain-branching reactions that would result in detonation (i.e., knock). Thus,tetraethyllead is a gasoline-soluble and volatile source of lead atoms at the operating temperature of the engine. It is not the intact molecule which is the effective antiknock agent; it is merely a lead carrier.
  10. ^ Nriagu, Jerome O. (1 March 1990). "The rise and fall of leaded gasoline". Science of the Total Environment. 92: 13–28. Bibcode:1990ScTEn..92...13N. doi:10.1016/0048-9697(90)90318-O. ISSN 0048-9697.
  11. ^ Hewitt, C Nicholas; Rashed, M B (1988). "Organic lead compounds in vehicle exhaust". Applied Organometallic Chemistry. 2 (2): 95–100. doi:10.1002/aoc.590020202. ISSN 1099-0739. Of the alkyllead additive in fuel about. 75% is emitted from the exhaust as a complex mixture of inorganic lead salts with the majority of the remainder being deposited in the engine and exhaust system.
  12. ^ "LEAD EXPOSURE IN CHILDHOOD LINKED TO LOWER IQ, LOWER STATUS: Leaded gasoline creates a natural experiment in long-term study". Duke University. 28 March 2017. Archived from the original on 13 July 2024. Retrieved 11 March 2022.
  13. ^ Carocci, Alessia; Catalano, Alessia; Lauria, Graziantonio; Sinicropi, Maria Stefania; Genchi, Giuseppe (2016), de Voogt, Pim (ed.), "Lead Toxicity, Antioxidant Defense and Environment", Reviews of Environmental Contamination and Toxicology Volume 238, vol. 238, Cham: Springer International Publishing, pp. 45–67, doi:10.1007/398_2015_5003, ISBN 978-3-319-30790-9, PMID 26670034, retrieved 19 May 2025
  14. ^ Grant, Lester D. (2020), "Lead and Compounds", Environmental Toxicants, John Wiley & Sons, Ltd, p. 660, doi:10.1002/9781119438922.ch17, ISBN 978-1-119-43892-2, retrieved 20 May 2025, The extreme tenacity for phosphate may be the most distinctive feature of Pb chemistry relative to other divalent metal ions.... It is also compatible with the ultimate localization of the Pb in bone as insoluble phosphate salts.
  15. ^ Newell R. G.; Rogers. K. The market-based lead-phasedown. Resources for the Future (Discussion paper) 2003, 3-37.
  16. ^ "It's official: You can't buy leaded gasoline for cars anywhere on Earth". cbc.ca. CBC News. 30 August 2021. Archived from the original on 30 August 2021. Retrieved 30 August 2021.
  17. ^ Tsai, Peter L.; Hatfield, Thomas H. (2011). "Global Benefits From the Phaseout of Leaded Fuel". Journal of Environmental Health. 74 (5): 8–15. ISSN 0022-0892. JSTOR 26329321.

Rich TVX News Network Site

Rich TVX News Network Info

© MMXXIII Rich X Search. We shall prevail. All rights reserved. Rich X Search