IUPAC name: (3R,4S,5R)-3,4,5-Trihydroxycyclohexene-1-carboxylic acid
Molecular Formula: C₇H₁₀O₅
Molecular Weight: 174.15 g/mol
EINECS: 205-334-2
Melting point: 185-191 °C
alpha: -180 º (c=4, H2O 25 °C)
Water solubility: 18 g/100 mL (20 °C) 
Index of Refraction: 1.679 
Sensitive: Hygroscopic
Merck: 14,8480 
Density: 1.725 g/cm³
Flash Point: 210.1 °C
Surface Tension: 116.6 dyne/cm
Enthalpy of Vaporization: 75.28 kJ/mol
Boiling Point: 400.5 °C at 760 mmHg
Vapour Pressure: 4.45E-08 mmHg at 25 °C
Product Category of Shikimic acid (CAS NO.138-59-0): API intermediates;Chiral Reagents;Chiral Building Blocks;Simple Alcohols (Chiral);Synthetic Organic Chemistry;Natural Plant Extract
Following is the structure of Shikimic acid (CAS NO.138-59-0):
        

Naturally, Shikimic acid (CAS NO.138-59-0) occurring (-)-form is a major biosynthetic precursor of phenylalanine, tyrosine, and tryptophan and hence of the majority of plant alkaloids. It is also involved in the biosynthesis of lignin, flavonpids and other important aromatic substance.

 Shikimic acid (CAS NO.138-59-0) has been listed as a carcinogen by IARC in Group 3. The toxicological properties have not been fully investigated. You can see actual entry in RTECS for complete information.

IARC Cancer Review: Group 3 IMEMDT . IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 7 ,1987,p. 56.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) ; Animal Inadequate Evidence IMEMDT IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 40 ,1986,p. 47.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) . EPA Genetic Toxicology Program.

 Shikimic acid's safety information: Moderately toxic by intraperitoneal route. Questionable carcinogen with experimental tumorigenic data. Mutation data reported. When heated to decomposition, it emits acrid smoke and irritating fumes.
Hazard Codes: Xi
Risk Statements: 36/37/38
R37/38:Irritating to respiratory system and skin.
Safety Statements: 22-24/25-36-26 
S22:Do not breathe dust.
S24/25:Avoid contact with skin and eyes. 
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S36:Wear suitable protective clothing.
WGK Germany: 3
RTECS: GW4600000
F: 3-10
HS Code: 29181980 

 Shikimic acid , with a CAS number of 138-59-0, known as 3R,4S,5R)-(-)-3,4,5-Trihydroxy-1-cyclohexenecarboxylic acid ; and 3,4,5-Trihydroxy-1-cyclohexene-1-carboxylic acid . And its classification code are mutation data, natural product, tumor data. Shikimic acid (CAS NO.138-59-0) could be stable under normal temperatures and pressures. And it should avoid the condition like strong oxidants. And also prevent it to broken down into hazardous decomposition products: carbon monoxide, irritating and toxic fumes and gases, carbon dioxide. Its hazardous polymerization has not been reported.