4-Methylbenzylidene camphor[1]
IUPAC name	(3E)-1,7,7-Trimethyl-3-[(4-methylphenyl)methylene]-2-norbornanone
Other names	3-(4-Methylbenzylidene)bornan-2-one 3-(4-Methylbenzylidene)-dl-camphor
Identifiers
Abbreviations	4-MBC
CAS number	36861-47-9
PubChem	6434217
EC number	253-242-6
SMILES	O=C2\C(=C\c1ccc(cc1)C)C3CCC2(C)C3(C)C
InChI	1/C18H22O/c1-12-5-7-13(8-6-12)11-14-15-9-10-18(4,16(14)19)17(15,2)3/h5-8,11,15H,9-10H2,1-4H3/b14-11+
InChI key	HEOCBCNFKCOKBX-SDNWHVSQBW
ChemSpider ID	4939160
Properties
Molecular formula	C18H22O
Molar mass	254.37 g/mol
Appearance	White crystalline powder
Melting point	66-69 °C
Solubility in water	Insoluble
Hazards
R-phrases	R36/37/38 R50 R53
S-phrases	S26 S37/39 S61
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

4-Methylbenzylidene camphor (4-MBC) 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).

[edit] 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]

[edit] 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.^{[citation needed]}

[edit] Approval status

4-MBC is approved for use in Europe by the European Union's Scientific Committee for Cosmetic Products & Non-Food Products and 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.

[edit] See also

• Xenoestrogen

[edit] References