PMID- 15779749
OWN - NLM
STAT- MEDLINE
DCOM- 20051115
LR  - 20190917
IS  - 0730-7268 (Print)
IS  - 0730-7268 (Linking)
VI  - 24
IP  - 3
DP  - 2005 Mar
TI  - Aqueous photochemistry of triclosan: formation of 2,4-dichlorophenol, 
      2,8-dichlorodibenzo-p-dioxin, and oligomerization products.
PG  - 517-25
AB  - The photochemical fate of the antimicrobial agent triclosan is presented. 
      Experiments performed in both natural and buffered deionized water show that 
      triclosan rapidly photodegrades by direct photolysis (t(1/2) = 5 h, pH 8, noon 
      summer sunlight, 45 degrees N latitude). Both 2,8-dichlorodibenzo-p-dioxin 
      (2,8-DCDD) and 2,4-dichlorophenol (2,4-DCP) are produced. The 2,8-DCDD and 
      2,4-DCP also are photolabile and, thus, are intermediates. The yields for 
      2,8-DCDD and 2,4-DCP ranged from 3 to 12% depending on the conditions employed. 
      When triclosan is photolyzed in the presence of Suwannee River (GA, USA) fulvic 
      acid, a portion of the initial mass is recovered as insoluble material. Based on 
      experiments in which the formation of insoluble material was monitored with 
      photolysis time, it is postulated that photolysis in natural waters leads to some 
      of the triclosan being coupled to humic matter. Triclosan also reacts rapidly 
      with both singlet oxygen (k(rxn) = 1.07 +/- 0.03 x 10(8) M(-1) s(-1) in water of 
      pH 10) and hydroxyl radical (k(*OH) = 5.4 +/- 0.3 X 10(9) M(-1)(s-1). Indirect 
      photolysis pathways, however, are not expected to be important because of low 
      steady-state concentrations of reactive oxygen species in natural waters and the 
      efficiency of the direct photolysis of triclosan.
FAU - Latch, Douglas E
AU  - Latch DE
AD  - Department of Chemistry, University of Minnesota, 207 Pleasant Street Southeast, 
      Minneapolis, Minnesota 55455, USA.
FAU - Packer, Jennifer L
AU  - Packer JL
FAU - Stender, Brian L
AU  - Stender BL
FAU - VanOverbeke, Jennifer
AU  - VanOverbeke J
FAU - Arnold, William A
AU  - Arnold WA
FAU - McNeill, Kristopher
AU  - McNeill K
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - Environ Toxicol Chem
JT  - Environmental toxicology and chemistry
JID - 8308958
RN  - 0 (Anti-Infective Agents, Local)
RN  - 0 (Benzopyrans)
RN  - 0 (Chlorophenols)
RN  - 0 (Dioxins)
RN  - 17778-80-2 (Singlet Oxygen)
RN  - 3352-57-6 (Hydroxyl Radical)
RN  - 4NM5039Y5X (Triclosan)
RN  - JPA391PZI1 (2,8-dichlorodibenzo-4-dioxin)
RN  - R669TG1950 (2,4-dichlorophenol)
RN  - XII14C5FXV (fulvic acid)
SB  - IM
MH  - Anti-Infective Agents, Local/*chemistry
MH  - Benzopyrans/chemistry
MH  - Chlorophenols/chemistry
MH  - Dioxins/chemistry
MH  - Georgia
MH  - Hydroxyl Radical/chemistry
MH  - Minnesota
MH  - *Photolysis
MH  - Rivers/chemistry
MH  - Seasons
MH  - Singlet Oxygen/chemistry
MH  - Sunlight
MH  - Triclosan/*chemistry
EDAT- 2005/03/23 09:00
MHDA- 2005/11/16 09:00
CRDT- 2005/03/23 09:00
PHST- 2005/03/23 09:00 [pubmed]
PHST- 2005/11/16 09:00 [medline]
PHST- 2005/03/23 09:00 [entrez]
AID - 10.1897/04-243r.1 [doi]
PST - ppublish
SO  - Environ Toxicol Chem. 2005 Mar;24(3):517-25. doi: 10.1897/04-243r.1.