4-Methylbenzylidene camphor

4-Methylbenzylidene camphor[1]
Skeletal formula of 4-methylbenzylidene camphor
Ball-and-stick model of the 4-methylbenzylidene camphor molecule
Names
IUPAC name
(3E)-1,7,7-Trimethyl-3-[(4-methylphenyl)methylene]-2-norbornanone
Other names
Enzacamene; 3-(4-Methylbenzylidene)bornan-2-one
3-(4-Methylbenzylidene)-dl-camphor
Identifiers
36861-47-9 N
3D model (Jmol) Interactive image
Abbreviations 4-MBC
ChemSpider 4939160 YesY
ECHA InfoCard 100.048.386
EC Number 253-242-6
PubChem 6434217
Properties
C18H22O
Molar mass 254.37 g/mol
Appearance White crystalline powder
Melting point 66 to 69 °C (151 to 156 °F; 339 to 342 K)
Insoluble
Hazards
Main hazards Xi
R-phrases R36/37/38 R50 R53
S-phrases S26 S37/39 S61
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YesYN ?)
Infobox references

4-Methylbenzylidene camphor (4-MBC, enzacamene) is an organic camphor derivative that is used in the cosmetic industry for its ability to protect the skin against UV, specifically UV B radiation. As such it is used in sunscreen lotions and other skincare products claiming a SPF value. Its tradenames include Eusolex 6300 (Merck) and Parsol 5000 (DSM).

Mechanism

All the camphor sunscreens are supposed to dissipate the photon energy by cis-trans isomerisation. But for 4-MBC the quantum yield for this isomerisation is reported to be only between 0.13 - 0.3. This low quantum yield means that other photochemical processes are occurring.[2]

Endocrine disruptor

Studies have raised the issue that 4-MBC acts an endocrine disruptor. There is controversy about the estrogenic effects of 4-MBC and while one study showed only a relatively minor effect,[3] a study in Switzerland showed significant uterine growth in immature rodents.[4] In addition, there is some evidence that 4-MBC may suppress the pituitary-thyroid axis leading to hypothyroidism.[5]

The agent can also lead to a photoallergic dermatitis.

Approval status

4-MBC has been banned for use in Europe by the European Union since 2015.[6] It is approved in Canada by Health Canada. It is not approved for use in the USA by the Food and Drug Administration and it is not permitted in Japan.

See also

References

  1. 3-(4-METHYLBENZYLIDEN)CAMPHOR at chemicalland21.com
  2. Sun Protection in Man. Chapter 26: Cantrell, Ann; McGarvey, David J.; Truscott, T. George. Photochemical and photophysical properties of sunscreens.
  3. Mueller SO; Kling M; Arifin Firzani P; et al. (April 2003). "Activation of estrogen receptor alpha and ERbeta by 4-methylbenzylidene-camphor in human and rat cells: comparison with phyto- and xenoestrogens". Toxicol. Lett. 142 (1-2): 89–101. doi:10.1016/S0378-4274(03)00016-X. PMID 12765243.
  4. Sun Block has Endocrine Disruptor Chemicals, New Scientist, April 18, 2001
  5. IH Hamann; C Schmutzler; P Kirschmeyer; H Jarry & J Köhrle (2006). "4-Methylbenzylidene-camphor (4MBC) causes pituitary effects comparable to hypothyroidism". Endocrine Abstracts. 11: OC60.
  6. http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32015R1298&from=EN
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