|Appearance||colorless/white crystals or powder|
|Melting point||157 to 159 °C (315 to 318 °F; 430 to 432 K)|
|Main hazards||potential occupational carcinogen|
|R-phrases||R48/22 R51/53 R63|
|S-phrases||(S2) S13 S36/37 S61|
|US health exposure limits (NIOSH):|
|Ca TWA 0.2 mg/m3|
IDLH (Immediate danger)
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
|what is: / ?)(|
3-AT is a competitive inhibitor of the product of the HIS3 gene, imidazoleglycerol-phosphate dehydratase. Imidazoleglycerol-phosphate dehydratase is an enzyme catalysing the sixth step of histidine production.
3-AT is also a nonselective systemic triazole herbicide used on nonfood croplands to control annual grasses and broadleaf and aquatic weeds. It is not used on food crops because of its carcinogenic properties. As an herbicide, it is known as aminotriazole, amitrole or amitrol.
Applications in microbiology
By applying 3-AT to a yeast cell culture which is dependent upon a plasmid containing HIS3 to produce histidine (i.e. its own HIS3 analogue is not present or nonfunctional), an increased level of HIS3 expression is required in order for the yeast cell to survive. This has proved useful in various two-hybrid system, where a high-affinity binding between two proteins (i.e., higher expression of the HIS3 gene) will allow the yeast cell to survive in media containing higher concentrations of 3-AT. This selection process is performed using selective media, containing no histidine.
1959 cranberry contamination
On November 9, 1959, the secretary of the United States Department of Health, Education, and Welfare Arthur S. Flemming announced that some of the 1959 crop was tainted with traces of the herbicide aminotriazole.  The market for cranberries collapsed and growers lost millions of dollars. 
- EXTOXNET - Herbicide fact sheet for amitrole
- "NIOSH Pocket Guide to Chemical Hazards #0027". National Institute for Occupational Safety and Health (NIOSH).
- Joung, J. K., E. I. Ramm and C. O. Pabo (2000). "A bacterial two-hybrid selection system for studying protein-DNA and protein-protein interactions." Proc Natl Acad Sci U S A 97(13): 7382-7.
- "Interpretation of criteria for approval of active substances in the proposed EU plant protection regulation". Swedish Chemicals Agency (KemI). 2008-09-23. Archived from the original on 1 January 2009. Retrieved 2009-01-14.
- "MEPs approve pesticides legislation". 2009-01-13. Archived from the original on 25 January 2009. Retrieved 2009-01-14.
- "Safe Cranberries to Go on Sale". Dubuqe Telegraph-Herald. 19 November 1959. Retrieved 10 February 2012.
- New York Times website - Opinion section