Feughelman, 1982  Title: Physical properties of alpha-keratin
fibers
Author: Feughelman, M
Journal: J Soc Cosmetic Chemists, 33:385-406,
Dec 1982
Alpha-keratin fibers are produced by mammals as nails and hair.
This article was submitted to FDA as part of the 510(k) submission
of Guaranty Hair Removal (GHR) ( Stephens, 1990). Stephens Manufacturing
continues to claim the article proves that the GHR electric tweezer
can cause enough electricity to travel through a hair to kill
a hair follicle.
In reality, Feughelman's findings refute GHR's claims.
Summary of Feughelman's findings
Hair is a poor conductor of electricity
Feughelman notes that fibers with 7% water content have a
resistivity 3 x 1012 ohm-cm at room temperature
(p. 392)
Even hair with high moisture is a poor
conductor of electricity
He states: "The electrical conductivity of an alpha-keratin
fiber is very dependent on the water content of the fiber"
(p. 392). Feughelman also notes that even fibers with high
water content (25%) have a resistivity 6 x 106
ohm-cm at room temperature (p. 392)
Hair internal structures absorb water
poorly
He states: "Ample evidence exists for the presence of
a highly ordered structure of low water penetrability within
the keratin fibers" (p. 393). And: "X-ray evidence
suggests that water sorbtion in an alpha-keratin fiber is
mainly confined to the non-crystalline regions" (p. 391).
He concludes: "Again the evidence points strongly to
the lack of interaction of water with the organized alpha-helical
structure within the keratin fibers" (392).
Feughelman reviews other conductivity tests
Because electric tweezer makers have cited him as an authority,
Dr. Feughelman was asked to review the unpublished clinical data
of Mark van Orden of R.A. Fisher Co.
van Orden, 1998
The van Orden tests again show that hair is a poor conductor
of electricity, and that hair itself cannot conduct enough electricity
through the shaft to kill the root, a common claim by electric
tweezers. Dr. Feughelman describes keratin found in hairs as a
form of protonic semiconductor (as opposed to an electronic
semiconductor) and that the indicated water content of a hair
fiber is not liquid water, but at best a hydrogen bonded network
of H2O molecules. Feughelman states that "hair
is an excellent insulator" and such water content in the
hair would not conduct measurable current.
Feughelman concludes:
"All the calculations made by R.A. Fischer Co. Inc. have
been checked by me and I find them correct. I have read through
the Human Hair Conductivity Tests by the laboratories R.A. Fischer
Co. Inc. and commend their thoroughness. As expected the tests
show no measurable current at the microamp level. The only way
to obtain any significant current flow would be to apply to
the hair fibre some kind of conducting electrolyte in the form
of possibly a gel to obtain sufficient conduction on each hair
fibre."
Feughelman on conductive gels applied to hair
Because electric tweezers like GHR use a conductive gel, Feughelman
further confirmed that the application of a gel or conductive
solution would form a coating on the hair surface through which
current might flow, not through the hair fiber itself.
Dr. Feughelman's comments echo concerns of other specialists,
who question GHR's effectiveness. The specialists below both discuss
how electricity traveling down the outer hair shaft would dissipate
when it reached the skin.
FDA Special Product Engineer Paul Ruggera,
( Ruggera, 1991),
who reviewed the GHR 510(k) submission ( Stephens, 1990)
Dermatologist James Schuster, M.D.
( Schuster, 1992).
Acknowledgement: Thanks to Max Feughelman for his insights
and to Mark van Orden for sharing personal correspondence.
Credentials: Dr. Max Feughelman, BSc, DSc, ASTC, FAIP, is Professor
Emeritus of the School of Fiber Science and Technology at University
of New South Wales, Sydney. He is an expert in the physical properties
of human hair. He contributed the chapters on hair characteristics
in Hair and Hair Care (ed. by Dale H. Johnson New York,
NY, Marcel Dekker Inc, 1997) and serves as director of Fibrous
Keratin Consultants in NSW, Australia. He is also author of Mechanical
Properties and Structure of Alpha-Keratin Fibres: Wool, Human
Hair, and Related Fibres, (University of New South Wales
Press, Sydney, Australia. 1st Edition, 1997).
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