triclosan structure, again

[ttweed@wildrockies.org (Tony Tweedale)]

I received 3 corrections on my description of the structure of the consumer
product antimicrobial triclosan.  I forgot from when I had looked at its
structure (http://chemfinder.camsoft.com/   is v. handy for that) that it
can rotate v. freely around the single bridging O, it isn't likely to have
simple planar toxicity.  but then a lot of PCBs are similar, tho I don't
think they rotate quite as freely, w/out having an O bridge.   anyway, jon
campbell & jj jacobson have some good stuff, so I took the liberty of
posting it here again.

sorry I don't have the cite for the top of p. B1 WSJ article, which was
from an advertising slant and didn't say much else other than it is likely
more toothpastes will get antimicrobe FDA approval, which will be used in
marketing.
---

Hi, Tony,

I believe triclosan is different than TCDD structurally. There is only one
oxygen between the benzene rings, rather than two, which makes it a
dibenzyl ether rather than a dibenzo dioxin.

See the URL: http://www.mc.vanderbilt.edu/vumcdept/derm/contact/TR004.html

Now, I agree with you that triclosan is probably very dangerous. First of
all, it is a trichloro-dibenzene compound, and we know that the
manufacturing of such compounds create dioxin, both as a by-product and as
a severe contaminant. Second, it is just a couple of steps away from TCDD.
Minor oxidation might convert it. Third, its structure is half-way between
PCBs (no oxygen between the benzene rings) and PCDDs (two oxygens between
them). The likelihood that PCBs are really bad, PCDDs are really really
bad, and triclosan is innocuous is a real stretch of the imagination.
Fourthly, almost all of the citations that I have found so far for
triclosan come from a single collection of papers or studies from two
symposia, referred to in RTECS as 26UZAB, Pesticides Symposia, collection
of papers presented at the Sixth and Seventh Inter-American Conferences on
Toxicology and Occupational Medicine, Miami, FL, Univ of Miami School of
Medicine, 1968-70. This is a tad suspicious, but I don't exactly have
access.

Cheers
Jon Campbell

---

To: ttweed@wildrockies.0rg      Subject: triclosan
1/21/98

Dear Tony,
Glad you are keeping attention on triclosan. To keep your credibility,
please do not say the only difference between triclosan and dioxin (which
usually stands for 2,3,7,8 TCCD) is a OH in place of a chlorine. Triclosan
is a 2,4,4'-trichloro-2' hydroxydiphenyl ether... a 2,3,7,8 formation is a
little different from a 2,4,4'-2'.
Below is the information on triclosan I sent to the dioxin list in March,
when you noticed it. Triclosan is patented for its ability to select for
Pseudomonas, which can cause serious infections in hospital and other
closed situations. FDA recommended against various uses of triclosan 20
years ago, and warned against multiple uses. I never could get anyone
interested in deodorant soaps since that time.I wonder why they approved it
for putting in one's mouth. The FDA estimated about 10% of the triclosan
used taking a shower would be absorbed into the body. It can be measured in
blood plasma. Try to read the FR notice cited below.
What did the WSJ say when on triclosan?
Next on the list is fluoridation of drinking water. If you have not seen
the Griffiths/Bryson story in Waste Not on the secret army research on
fluoride due to its use making atomic bombs, I could mail it to you, if you
send a snail mail address.

JJ Jacobson


3/17/97 Triclosan and the Anti-Microbial Craze

Triclosan is a trichlorinated phenoxyphenol (manufactured by Ciba-Geigy)
that appears in many anti-bacterial formulations and products. It is also
known as Irgasan DP300 and Sanitized®. It is listed as "could be" and
"suspected to be" contaminated with dioxins in EPA's Dioxin Reassessment
(Exposure Estimates vol. II p. 3-47 and p. 3-54).
The formula is 5-chloro-2-(2,4-dichlorophenoxy)phenol. The CAS number is
3380-34-5. The EPA Shaughnessey Code is 054901.
The structure is similar to the Agent Orange herbicides, 2,4,5-T and 2,4-D,
and to dioxin and hexachlorophene.
In 1980 Ciba-Geigy sued Industrial Bio-Test Laboratories, Inc (IBT) for
gross negligence in connection with toxicity evaluation tests run between
1966 and mid-1977 on 100 pesticides and related compounds (Chem & Eng News
June 30, 1980).
In 1981 triclosan/Irgasan appeared on a list of chemicals tested by IBT
before IBT officials went to jail for falsification of data.
When the Center for the Biology of Natural Systems asked Ciba-Geigy in May
1980 to verify that triclosan does not contain dioxins as contaminants, the
reply stated that TCDD and other highly chlorinated dioxins are toxic, but
"numerous studies have shown that dioxins with 3 or less chloro groups are
comparatively non-toxic". In addition, said Ciba-Geigy, Irgasan DP 300 is
99+% pure, and "We verify that no highly chlorinated dioxin including TCDD
exists in our product."
Most of the comments on the current sales pitch for bactericides in
clothes, kitchen, and children's belongings recognize that indiscriminate
use of this type of pesticide encourages the development of populations of
resistant organisms. In 1978 FDA ( 2,4) pointed out that triclosan selected
so strongly for Pseudomonas aeruginosa that it should not be used in closed
settings like hospitals or nursing homes where serious infections could
arise.
Some newspaper stories warn that bactericides now advertised do not kill
viruses.
So far I have seen no concern for the effects of triclosan or other
bactericides and their contaminants on their users. Triclosan, which is
absorbed through intact skin, already is in "leave-on" products, such as
lotions and moisturizers, and Consumers Report says triclosan will soon
appear in toothpaste in the U.S. FDA was concerned in 1978 about its use in
small children, the elderly, or infirm. Triclosan caused liver damage in
dogs.
Triclocarban (3,4,4'-trichlorocarbanilide) caused testicular damage in rats
and replaced hexachlorophene in many deodorant soaps. No one seems to have
considered the frequent, intimate application of deodorant soaps as a
factor in lowered sperm counts or other endocrine disruption.
Liquid pHisohex contained 3% hexachlorophene. It was recommended for use on
babies, beginning during delivery, in hospital nurseries, and thereafter at
home. Mistakenly used as a lotion and in a dusting powder, it caused
convulsions, brain damage, and death. "Pure" hexachlorophene used to supply
10-20 parts per billion of dioxin. It should not be assumed that all damage
can be blamed on dioxin alone.
Chlorinated phenols are known to damage the immune system. How is
indiscriminate use of antibacterials that damage your immune system helping
to protect you from bacterial scourges created by the very use of these
same chemicals? Are there ethical questions here? Should an advertisement
have to agree with the label, and no puffery allowed?
Cosmeceuticals should be formulated under regulations for drugs, not those
for cosmetics, no matter what the intent of the formulater.

1. Christopher Norwood At Highest Risk 1980 p. 201
2. Federal Register vol. 43, no. 4, p.1231-32 Fri. Jan.6, 1978
3. EPA Dioxin Reassessment (Exposure Estimates vol. II p.3-47 and p. 3-54).
4. Fed Reg 1/6/78 p.1233
5. C&EN 3/3/97 p.22


Tony Tweedale
Causality is a concept not subject to empirical demonstration.   -David
Hume (1711-'76)