4-Methylbenzylidene camphor

chembox new
Reference= [ [http://www.chemicalland21.com/specialtychem/finechem/3-(4-METHYLBENZYLIDEN)CAMPHOR.htm 3-(4-METHYLBENZYLIDEN)CAMPHOR] at chemicalland21.com]
ImageFile=4-Methylbenzylidene camphor.svg
ImageSize=200px
IUPACName=(3"E")-1,7,7-Trimethyl-3- [(4-methylphenyl)methylene] -2-norbornanone
OtherNames= 3-(4-Methylbenzylidene)bornan-2-one
3-(4-Methylbenzylidene)-dl-camphor
Section1=Chembox Identifiers
Abbreviations = 4-MBC
CASNo=36861-47-9
EINECS=253-242-6
PubChem=6434217
SMILES=CC1=CC=C(C=C1)C=C2C3CCC(C2=O)(C3(C)C)C
Section2=Chembox Properties
Formula=C₁₈H₂₂O
MolarMass=254.37 g/mol
Appearance=White crystalline powder
Density=
MeltingPt=66-69 °C
BoilingPt=
Solubility=Insoluble
Section3=Chembox Hazards
MainHazards=Xi
FlashPt=
Autoignition=
RPhrases= R36/37/38 R50 R53
SPhrases = S26 S37/39 S61

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 deodorants. 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. ["Sun Protection in Man". Chapter 26: Cantrell, Ann; McGarvey, David J.; Truscott, T. George. Photochemical and photophysical properties of sunscreens.]

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, [cite journal |author=Mueller SO, Kling M, Arifin Firzani P, "et al" |title=Activation of estrogen receptor alpha and ERbeta by 4-methylbenzylidene-camphor in human and rat cells: comparison with phyto- and xenoestrogens |journal=Toxicol. Lett. |volume=142 |issue=1-2 |pages=89–101 |year=2003 |month=April |pmid=12765243 |doi= |url=http://linkinghub.elsevier.com/retrieve/pii/S037842740300016X] a study in Switzerland showed significant uterine growth in immature rodents. [ [http://www.mindfully.org/Health/Sun-Screens-EDs.htm Sun Block has Endocrine Disruptor Chemicals] , "New Scientist", April 18, 2001] In addition, there is some evidence that 4-MBC may suppress the pituitary-thyroid axis leading to hypothyroidism. [cite journal| journal=Endocrine Abstracts |year=2006 |volume=11 |pages=OC60 |title=4-Methylbenzylidene-camphor (4MBC) causes pituitary effects comparable to hypothyroidism |author=IH Hamann, C Schmutzler, P Kirschmeyer, H Jarry & J Köhrle |url=http://www.endocrine-abstracts.org/ea/0011/ea0011oc60.htm]

The agent can also lead to a photoallergic dermatitis.Fact|date=July 2008

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.

Alternative agents

Alternative agents that block UV by absorption include:
* Avobenzone
* Homosalate
* Octyl methoxycinnamate (OMC)
* Oxybenzone

ee also

Xenoestrogen

References