Chemistry informtion about N-Butylurea (CAS NO.592-31-4) is:
IUPAC Name: Butylurea
Synonyms: 1-Butylurea ; Butyl-Ure ; Monobutylurea ; Nci-C02131 ; N-N-Butylurea ; Urea,N-Butyl- ; N-Butylurea ; Butylurea
Product Categories: Carbonyl Compounds ; Organic Building Blocks ; Ureas
MF: C₅H₁₂N₂O
MW: 116.16
EINECS: 209-748-4
Density: 0.962 g/cm³
Melting Point: 95-98 °C(lit.)
 Flash Point: 62.3 °C
Boiling Point: 179.4 °C at 760 mmHg
Vapour Pressure: 0.944 mmHg at 25°C
Enthalpy of Vaporization: 41.57 kJ/mol
Following is the molecular structure of N-Butylurea (CAS NO.592-31-4) is:

Reported in EPA TSCA Inventory. EPA Genetic Toxicology Program.

Moderately toxic by parenteral route. Mutation data reported. When heated to decomposition it emits toxic fumes of NO_x.
Hazard Codes:
Xn
Risk Statements:
R22:Harmful if swallowed. 
R68:Possible risk of irreversible effects. 
R37:Irritating to respiratory system 
R20/21/22:Harmful by inhalation, in contact with skin and if swallowed.
Safety Statements:
S45:In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) 
S36/37:Wear suitable protective clothing and gloves.
WGK Germany: 3
RTECS: YS3675000

 N-Butylurea (CAS NO.592-31-4) is a white to almost white crystalline powder.And it can soluble in water.It is an amide. Amides/imides react with azo and diazo compounds to generate toxic gases. Flammable gases are formed by the reaction of organic amides/imides with strong reducing agents. Amides are very weak bases (weaker than water). Imides are less basic yet and in fact react with strong bases to form salts. That is, they can react as acids. Mixing amides with dehydrating agents such as P₂O₅ or SOCl₂ generates the corresponding nitrile. The combustion of these compounds generates mixed oxides of nitrogen (NOx). N-Butylurea decomposes on heating. N-Butylurea emits toxic fumes when heated to decomposition. It is probably combustible.