Chemistry informtion about N,N-Dimethyl-P-Nitrosoaniline (CAS NO.138-89-6) is:
IUPAC Name: N,N-Dimethyl-4-Nitrosoaniline
Synonyms: 4-(Dimethylamino)Nitrosobenzene ; 4-Nitrosodimethylaniline ; Accelerene ; Accelerine ; Aniline, N,N-Dimethyl-P-Nitroso- ; Benzenamine,N,N-Dimethyl-4-Nitroso- ; Dimethyl-(4-Nitroso-Phenyl)-Amine ; Dimethyl(P-Nitrosophenyl)Amine
Product Categories: Intermediates of Dyes and Pigments
MF: C₈H₁₀N₂O
MW: 150.18
EINECS: 205-343-1
Density: 1.04 g/cm3
Melting Point: 85-87 °C(lit.) 
Flash Point: 110.3 °C
Boiling Point: 258.7 °C at 760 mmHg
Vapour Pressure: 0.0135 mmHg at 25°C 
Enthalpy of Vaporization: 49.64 kJ/mol
Storage temp.:  Flammables area
Merck: 14,6638
BRN: 607293
Stability: Stable. Incompatible with strong oxidizing agents, strong reducing agents, strong acids, acetic acid, acetic anhydride. Highly flammable
Following is the molecular structure of Pentyl nitrite (463-04-7) is:

Preparation products is Ethyl vanillin --> 2,4-Dinitrobenzaldehyde --> Gallocyanine

Reported in EPA TSCA Inventory.

Poison by ingestion. Mutation data reported. Questionable carcinogen with experimental tumorigenic data. Flammable when exposed to heat, flame, or oxidizers. Violent reaction with acetic anhydride + acetic acid. When heated to decomposition it emits toxic fumes of NO_x.
Hazard Codes:
F
T
Risk Statements:
R11:Highly flammable. 
R25 :Toxic if swallowed. 
R36/37/38:Irritating to eyes, respiratory system and skin. 
R43:May cause sensitization by skin contact.
Safety Statements:
S16:Keep away from sources of ignition. 
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S36/37:Wear suitable protective clothing and gloves. 
S45:In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.)
RIDADR: UN 1369 4.2/PG 2
WGK Germany: 3
RTECS: BX7175000
F:
F 4.7: Do not heat over 70 °C
F 8: Photosensitive.
F 9: Keep under nitrogen.HazardClass: 4.2
PackingGroup: II

DOT Classification:  4.2; Label: Spontaneously Combustible

 N,N-Dimethyl-P-Nitrosoaniline (CAS NO.138-89-6) is a dark green crystalline solid. It is insoluble in water and harmful if ingested. Susceptible to spontaneous combustion upon exposure to air. Also it has a delayed violent reaction with acetic anhydride. Fire will produce irritating, corrosive and/or toxic gases. Inhalation of decomposition products may cause severe injury or death. Contact with substance may cause severe burns to skin and eyes. Runoff from fire control may cause pollution. It is a flammable/combustible material. May ignite on contact with moist air or moisture. May burn rapidly with flare-burning effect. Some react vigorously or explosively on contact with water. Some may decompose explosively when heated or involved in a fire. May re-ignite after fire is extinguished. Runoff may create fire or explosion hazard. Containers may explode when heated.