"dangerous agent" is correct and usable in written English
You could use it when referring to a person or agent who is deemed dangerous, either because of their behaviour or their line of work. For example, "The police were warned of a dangerous agent in the area."
"They said he was dangerous," Agent Furey said.
A Pentagon report on Monday said that the Mahdi Army, the armed militia loyal to the radical Shia cleric Moqtada al-Sadr, had eclipsed al-Qaida as the most dangerous agent of sectarian violence.
Our worst enemies could not have wished upon us a more dangerous agent of devastation and destruction.
Eventually, she became the most serious and dangerous agent in the organisation, yet really she is also deeply insecure about herself.
Seen in this light, a woman shrouded in store-bought polyester presents a brazen, dangerous agent provocateur to challenge the crumbling status quo.
Furthermore, the steady rise in the spread of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) requires rapid and reliable methods to identify resistant strains, as early identification allows adequate treatment, further preventing the transmission of the dangerous agent.
No one would use such dangerous agents except as a last resort in a desperate situation.
Also staged throughout the ducts would be devices for detecting dangerous agents like anthrax or smallpox.
The Army insists that the dangerous agents have always been swiftly detected and contained on site.
Why does the Iraqi declaration ignore these dangerous agents in its tally?
The licenses permit people to drive trucks that carry poisonous, flammable, or other dangerous agents.
