A 19-year-old Pennsylvania man allegedly sent a poisonous birthday card to his ex-girlfriend's current boyfriend, ABC News reported.

Nicholas Helman was arrested on Wednesday at his Hatboro home on charges of attempted murder, aggravated assault, risking a catastrophe, and other counts.

According to authorities, Helman told a colleague at work that he sent the card, prompting the co-worker to call police. One police called the man's home, officers spoke with the man's mother and asked if they had received their mall that day.

The woman told police her daughter was retrieving the mall as they were on the phone, leading authorities to tell her to instruct her daughter to place everything back in the mailbox until authorities arrived to investigate it. 

According to Philly.com, initial tests did not show any trace of ricin on the card. However, Helman admitted to using sodium hydroxide because it resembled anthrax.

"If properly deployed, the stuff he put in that envelope would have killed a whole bunch of people," Heckler added.

Helman will remain in custody until is preliminary hearing, scheduled for March 27. 

Bucks County District Attorney David Heckler said the toxin Helman made was "very potent."

"He made ricin," Heckler said, "and if you lick that card, you're dead."