Butylhydroxybutylnitrosamine (OH-BBN or BBN) is a chemical compound that is primarily used in laboratory research as a potent carcinogenic agent. It is known to induce tumors in various organs, particularly in the urinary bladder and liver, when administered to experimental animals.

The IUPAC name for Butylhydroxybutylnitrosamine is N-butyl-N-(4-hydroxybutyl)nitrosamine. Its molecular formula is C8H19NO3. It is a white to off-white crystalline powder, soluble in water and alcohol.

It is important to note that Butylhydroxybutylnitrosamine is not used in human medicine or therapy due to its carcinogenic properties. Its use is restricted to research purposes only, under controlled conditions and with appropriate safety measures in place.