Butylated hydroxytoluene

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Structural formula
Structure of butylated hydroxytoluene
General
Surname Butylated hydroxytoluene
other names
  • 2,6-di- tert- butyl- p -cresol
  • 3,5-bis (1,1-dimethylethyl) -4-hydroxytoluene
  • 3,5-di- tert- butyl-4-hydroxytoluene
  • Butylated hydroxytoluene
  • 2,6-di- tert- butyl-4-methylphenol
  • 2,6-bis (1,1-dimethylethyl) -4-methylphenol
  • E  321
  • BHT ( INCI )
Molecular formula C 15 H 24 O
Brief description

colorless and odorless, crystalline solid

External identifiers / databases
CAS number 128-37-0
EC number 204-881-4
ECHA InfoCard 100.004.439
PubChem 31404
Wikidata Q221945
properties
Molar mass 220.35 g mol −1
Physical state

firmly

density

1.05 g cm −3

Melting point

69-70 ° C

boiling point

265 ° C

Vapor pressure
  • 0.02 hPa (20 ° C)
  • 2.4 hPa (100 ° C)
solubility
  • practically insoluble in water (0.1–1.14 mg l −1 at 20 ° C)
  • readily soluble in ethanol (250 g l −1 )
  • soluble in fats
Refractive index

1.4859 (75 ° C)

safety instructions
GHS labeling of hazardous substances
09 - Dangerous for the environment

Caution

H and P phrases H: 410
P: 273
MAK
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Butylated hydroxytoluene (BHT) is a chemical compound from the groups of toluene derivatives or phenols , which is industrially produced and used in considerable quantities. Phytoplankton such as the green alga Botryococcus braunii and the cyanobacteria Cylindrospermopsis raciborskii , Microcystis aeruginosa and Oscillatoria sp. , such as by forming BHT GC-MS was detected.

Extraction and presentation

BHT can be produced in a Friedel-Crafts alkylation by reacting p -cresol (4-methylphenol) with isobutylene (2-methylpropene), with sulfuric acid serving as a catalyst:

Synthesis of BHT

Butylated hydroxytoluene is one of the chemical substances that are produced in large quantities (" High Production Volume Chemical ", HPVC) and for which the Organization for Economic Cooperation and Development (OECD) collects data on possible hazards (" Screening Information Dataset ", SIDS ) was made.

use

BHT is used in numerous consumer products, e.g. B. paints, waxes, cosmetics, pharmaceuticals or packaging materials, and also used as an approved food additive under the designation E 321 . It is mainly used as an antioxidant to prevent or slow down changes in products due to atmospheric oxygen. Its addition as a stabilizer to diethyl ether or tetrahydrofuran prevents the formation of dangerous ether peroxides.

It also serves to stabilize biodiesel .

In the 1980s, the effectiveness of BHT against herpes simplex viruses was established in hamsters. Allergic reactions of the test persons to BHT prevented further use in this area.

Analytics

Lipophilic gel chromatography on Sephadex LH 20 can be used to isolate the substance from oils and test materials containing fat. The qualitative and quantitative determination can be carried out by gas chromatography. The coupling of HPLC with mass spectrometry can also be used for the qualitative and quantitative determination of BHT after appropriate sample preparation .

Safety instructions / toxicology

In a review article, animal experiments with high doses of BHT were described: disorders of blood coagulation occurred, and liver tumors were observed in long-term studies. The International Agency for Research on Cancer (IARC) has classified BHT as unclassifiable.

Butylated hydroxytoluene was included in the EU's ongoing action plan ( CoRAP ) in 2016 in accordance with Regulation (EC) No. 1907/2006 (REACH) as part of substance evaluation . The effects of the substance on human health and the environment are re-evaluated and, if necessary, follow-up measures are initiated. Butylated hydroxytoluene uptake was caused by concerns about exposure of sensitive populations , exposure of workers , high (aggregated) tonnage and widespread use and as a potential endocrine disruptor . The re-evaluation has been running since 2016 and is carried out by France .

See also

Individual evidence

  1. ↑ Entry on E 321: Butylated hydroxytoluene (BHT) in the European database for food additives, accessed on June 27, 2020.
  2. ↑ Entry on BHT in the CosIng database of the EU Commission, accessed on March 21, 2020.
  3. ↑ a b c d e f g h i j Entry on 2,6-di-tert-butyl-p-cresol in the GESTIS substance database of the IFA , accessed on June 13, 2018(JavaScript required) .
  4. ↑ a b c d Entry on butylated hydroxytoluene. In: Römpp Online . Georg Thieme Verlag, accessed on August 4, 2017.
  5. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-148.
  6. ↑ Swiss Accident Insurance Fund (Suva): Limit values ​​- current MAK and BAT values (search for 128-37-0 or butylated hydroxytoluene ), accessed on November 2, 2015.
  7. ↑ B. Babu, JT Wu: Production of Natural Butylated Hydroxytoluene as an Antioxidant by Freshwater Phytoplankton . In: Journal of Phycology . tape 44 , no. 6 , December 2008, pp. 1447-1454 , doi : 10.1111 / j.1529-8817.2008.00596.x , PMID 27039859 ( edu.tw [PDF]).
  8. ↑ Helmut Fiege, Heinz-Werner Voges, Toshikazu Hamamoto, Sumio Umemura, Tadao Iwata, Hisaya Miki, Yasuhiro Fujita, Hans-Josef Buysch, Dorothea Garbe, Wilfried Paulus: Phenol Derivatives. In: Ullmann's Encyclopedia of Industrial Chemistry. Wiley-VCH, Weinheim 2002. doi : 10.1002 / 14356007.a19_313 Article Online Posting Date: June 15, 2000.
  9. ↑ OECD : Screening Information Dataset (SIDS) Initial Assessment Report (SIAR) for 2,6-di-tert-butyl-p-cresol , accessed on October 3, 2014.
  10. ↑ Patent EP1563041 : Use of 2,6-di- tert. -butyl- p -cresol to increase the storage stability of biodiesel. Registered on July 8, 2003 , published on July 2, 2008 , applicant: Lanxess , inventor: Axel Ingendoh, Christian Rother, Klaus-Peter Heise. ‌
  11. ↑ James T. Richards, Mary Ellen Katz, Earl R. Kern: Topical butylated hydroxytoluene treatment of genital herpes simplex virus infections of guinea pigs . In: Antiviral Research . tape 5 , no. 5 , October 1985, p. 281-290 , doi : 10.1016 / 0166-3542 (85) 90042-7 .
  12. ↑ H.-U. Melchert: Lipophilic gel chromatography for the isolation of BHA and BHT from vegetable oils. In: Chem. Microbiol. Technol. Food 2, 1973, pp. 94-85.
  13. ^ R. Liu, T. Ruan, S. Song, Y. Lin, G. Jiang: Determination of synthetic phenolic antioxidants and relative metabolites in sewage treatment plant and recipient river by high performance liquid chromatography-electrospray tandem mass spectrometry. In: J Chromatogr A. 1381, Feb 13, 2015, pp. 13-21. PMID 25614188 .
  14. ↑ Regine Kahl, Hermann Kappus: Toxicology of the synthetic antioxidants BHA and BHT, compared with the natural antioxidant vitamin E . In: Journal of Food Control and Research A . tape 196 , no. 4 , April 1, 1993, pp. 329-338 , doi : 10.1007 / BF01197931 .
  15. ↑ Community rolling action plan ( CoRAP ) of the European Chemicals Agency (ECHA): 2,6-di-tert-butyl-p-cresol , accessed on March 26, 2019.Template: CoRAP status / 2016