Probably not. Ricin is toxic.
ricin
Wood Green ricin plot happened in 2003.
Ricin
The production of ricin is a low-tech endeavor requiring little time or funding.
Hard to detect.but still it is possible. Doctors guess it by Symptom. There is a Special test designed to detect Ricin!
The active poison in the castor bean is ricin, a deadly water-soluble protein called a lectin.
It doesn't "become" toxic, it starts out that way.
Ricin
Ricin is a proteinic cytotoxin derived from the common castor bean, Ricinis communis. Recovered from the meal of castor beans in the castor oil making process, ricin toxin is perhaps 1,000 fold less toxin that botulinum toxin. Ricin is most toxic if inhaled and least toxic if swallowed. It has the potential to be used as a chemical warfare agent.
Ricin
Ricin
Ricin is a poison derived from castor beans. It can be made from the waste material after processing (mashing) castor beans into castor oil. Although not as lethal as anthrax, ricin prevents cells from producing protein and can lead to death within 36 to 72 hours. In 2013, a Mississippi man, Paul Kevin Curtis, was arrested for sending ricin-contaminated letters to a Mississippi senator and President Obama.