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Re:triclosan
On 29 July 1998, J. Menoutis, Ph.D., F.A.I.C., C.P.C., wrote
> I'm receiving a number of inquires regarding the anitmicrobal Triclosan and
> its possible risks. The concern is not over Triclosan itself , but rather over
> the trace impurities which can from as unwanted synthesis and manufacturing
> by-products. Depending on the manufacturing synthesis pathways used as well as
> the type of equipment used several different dioxins and dibenzofurans may be
> formed as product contaminants. These include 2,3,7,8-TCDD & 2,3,7,8-TCDF.
There are several scientific studies that suggest that there is,
indeed, a problem with Triclosan itself, as shown below:
---------------------
Kanetoshi, A., Katsura, E., Ogawa, H., Ohyama, T., Kaneshima, H.,
and Miura, T. Acute toxicity, percutaneous absorption and effects
on hepatic mixed function oxidase activities of 2,4,4'-trichloro-2'-
hydroxydiphenyl ether (Irgasan DP300) and its chlorinated
derivatives. Arch. Environ. Contam. and Toxicol. 23(1):91-8, 1992.
Acute toxicity of 2,4,4'-trichloro-2'-hydroxydiphenyl ether (Irgasan
DP300) (I0 and its three chlorinated derivatives, 2',3,4,4'-
tetrachloro-2- dhydroxydiphenyl ether (II), 2',4,4',5-tetrachloro-2-
hydroxydiphenyl ether (III) and 2',3,4,4',5-pentachloro-2-
hydroxydiphenyl ether (IV), in mice were examined by
intraperitoneal injection. ... These results show the high
percutaneous absorbability of Irgasan DP 300 and its chlorinated
derivatives. The intraperitoneal administration of III and IV to rats
induced hepatic microsomal aminopyrine N-dimethylase and
aniline 4-hydroxylase activities similarly to phenobarbital. These
chlorinated derivatives also increased cytochrome P-450 content
...
---------------------
DeSalva, S.J. Kong, B.M., and Lin, Y.J. Triclosan: a safety profile.
Am. J. Dentistry. 2 Spec No:185-96, 1989.
Triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether), an
antimicrobial agent, has been used extensively for 20 years in
consumer products, principally in deodorants, soaps and other
dermatological preparations. Recently, the use of triclosan has
been extended to oral health care products such as dentifrices.
This paper reviews safety information, both pre-clinical and clinical
studies, from the literature, data submitted to the Antimcrobial I
OTC Review Panel and unpublished work from the Pharmacology
and Toxicology Department of the Colgate-Palmolive Company.
...
In clinical studies with triclosan in solutions and dentifrices, a
steady state was reached by day 7 with blood levels in the parts
per billion (ppb) range and urine as the main route of excretion.
Based on these studies, triclosan can be considered safe for use
in dentifrice and mouthrinse products.
---------------
Source: Miller, T.L., Lorusso, D.J., and Deinzer, M.L. The acute
toxicity of nonachloropredioxin and 3- and 4-
hydroxynonachlorodiphenyl ether in mice. J. of Toxicol. and
Environ. Health 10(4-5):699-707, 1982
The acute intraperitoneal LD50 values of
hydroxynonachlorodiphenyl ethers (HO-C19-DPEs) in mice have
been determined. The acute toxicity of each of these compounds
is compared with that of pentachlorophenol (PCP) and 2-hydroxy-
2',4,4'-trichlorodiphenyl ether (2-OH-C19-DPE; Irgasan DP- 300;
Triclosan), a commonly used bactericide.
... 2-OH-C13-DPE, however, produced clinical signs suggestive
of a suppressive effect on the central nervous system.
---------------------
Roed-Petersen, J., Auken, G., Hjorth, N. Contact sensitivity to
Irgasan DP 300. Contact Dermatitis 1(5):293-4, 1975.
Two persons had allergic contact dermatitis caused by Irgasan
0,2% in a deodorant foot-powder and 0,12% in a deodorant stick
respectively. ... Although primary sensitization from Irgasan toilet
soaps has not been reported, a previously sensitized person may
react to the use of Irgasan in soaps.
------------------
DeSalva, S.J., Kong, B.M., and Lin, Y.-J. Triclosan: A safety
profile. Am.J. Dentistry 2 (Special Issue): 185-196. September
1989.
Triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether), an
antimicrobial agent, has been used extensively for 20 years in
consumer products, principally in deodorants, soaps and other
dermatological preparations. Recently, the use of triclosan has
been extended to oral health care products such as dentifrices.
...
The major contribution about the toxicological attributes of
triclosan per se was obtained from the reports submitted by the
Ciba-Geigy Company to the Hearing Clerk for the Antimicrobial I
OTC Review Panel.
...
A total of 1246 people have already used the experimental
toothpaste and mouthrinse products containing triclosan under
controlled conditions.
Table 15 shows the blood levels from four human studies. In the
21-day oral ingestion study, nine of the subjects drank a solution
containing triclosan and nine brushed their teeth, expectorated,
and rinsed their mouths. The significance is that following a total
consumption of 2 mg of triclosan twice a day in the aqueous
solution, the total triclosan blood level at 4 hours after the morning
dose ranged between 150 and 174 ppb whereas when brushing
twice a day with a toothpaste containing 2 mg of triclosan, the
blood level was between 15 and 21 ppb. In other studies, a
dentifrice containing triclosan was used at a concentration of 0.2,
0.3 or 0.6% and the blood levels ranged between 16 and 25 ppb.
In three other human studies (Table 16), the dermal route was
used to apply triclosan containing non-dental products. In one
case an aerosol containing triclosan was applied, while in the
second study a soap product containing 1% triclosan was used
daily for bathing and showering ( Colgate-Palmolive Company,
unpublished data), and in the third study leukemic patients
undergoing chemotherapy were bathed twice a day with a soap
containing 1% triclosan. In all three studies, the blood levels are in
ppb range. The bathing study was done with leukemic patients
and although the range for blood concentration appears wide, the
mean values were 4.5 ppb for free triclosan and 41.6 ppb for total
triclosan.
-----------------------
Source: Miller, T.L., Lorusso, D.J. and Deinzer, M.L. The acute
toxicity of nonachloropredioxin and 3- and 4-
hydroxynonachlorodiphenyl ether in mice. J. Toxic. Environ. Health
10:699-707 (1982)
Hydroxychlorodiphenyl ethers (HO-Clx-DPEs; chlorinated
phenoxyphenols; pre- and isopredioxins) are major contaminants
(1-5%) of technical pentachlorophenol (PCP) ... and other
chlorophenols ... and are chlorodiphenyl ether metabolites ... A
potential major source of environmental contamination with Ho-Clx-
DPEs is from the use of technical PCP in the United States in the
wood and wood products industry.
...
The bactericide 2-hydroxy-2',4,4'-trichlorodiphenyl ether (2- HO-
Cl3-DPE; Irgasan DP-300; Triclosan) is of relatively low acute oral
toxicity in rats (LD50 about 5000 mg/kg), while the acute
intravenous LD50 is 29 mg/kg ... This compound also causes liver
enlargement at a dose of 25 mg/kg (Kimbrough, 1974). The
bactericidal action of 2-HO-Cl3-DPE stems from an effect on the
bacterial membrane: i.e., membrane lesions induced by this
compound lead to leakage of cellular constituents and
subsequently to cell death ...
...
Results of the present work show that the HO-Clx-DPEs display
significant acute ip toxicity.
With the bactericide 2-HO-Cl3-DPE, the symptomology is not that
associated with an effect on oxidative phosphorylation but is more
typical of an encephalopathic effect as described by Boyd (1972).
Thus, the observed prolonged general lethargy, lack of response to
tactile stimuli, lassitude, weakness, and passive nature are
suggestive of a suppressive effect on the central nervous system ...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Pat Costner
Greenpeace
P.O. Box 548
or 512 County Road 2663
Eureka Springs, Arkansas 72632
ph: 1 501 253 8440
fx: 1 501 253 5540
em: pat.costner@dialb.greenpeace.org
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