Mutation data reported. When heated to decomposition it emits toxic fumes of NO_x
Safety Information 
Hazard Codes: T;N, 
T: Toxic   N: Dangerous for the environment 
Risk Statements: 45-20-36/38-51/53 
45: May cause cancer 
20: Harmful by inhalation  
36/38: Irritating to eyes and skin  
51/53: Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environmen  
Safety Statements: 53-45-61 
53: Avoid exposure - obtain special instruction before use  
45: In case of accident or if you feel unwell, seek medical advice immediately (show label where possible)  
61: Avoid release to the environment. Refer to special instructions safety data sheet  
RIDADR: 2926 
RTECS: MF4200000 
HazardClass: 4.1 
PackingGroup: II

Health Hazard and Fire Hazard of N-methyl-N&prime ; -Nitroguanidin (4245-76-5):
Health Hazard: Fire may produce irritating and/or toxic gases. Contact may cause burns to skin and eyes. Contact with molten substance may cause severe burns to skin and eyes. Runoff from fire control may cause pollution. 
Fire Hazard: Flammable/combustible material. May be ignited by friction, heat, sparks or flames. Some may burn rapidly with flare burning effect. Powders, dusts, shavings, borings, turnings or cuttings may explode or burn with explosive violence. Substance may be transported in a molten form at a temperature that may be above its flash point. May re-ignite after fire is extinguished.

EPA Genetic Toxicology Program.