All you need to do is spend some time going through US patents - you will find numerous safe ways to make Ricin. And "No" I will not tell you what patents to look at.
Because of the nature of ricin manufacture, much of it needs to be done in a cold environment - like a walk in refigerator. If not stored in a cold environment, it will quickly rot and be ineffective.
Fortunately, most government provided housing around where I live doesn't come supplied with walk-in refrigerators. It is highly unlikely that the government provided housing these terrorists had use of provided this equipment either. Since no mention of lab rats (to test purity) was mentioned, nor galleries of equipment to shell the castor beans and process it into something that doesn't need to be injested by the spoonfulls in order to be toxic, I seriously doubt that the batch of "ricin" was anything we should fear.
The fact that this was done in public housing is testimony enough that they didn't have the facilities to make anything too serious. Ricin's manufacture is not trivial, and the various processes for purification of the product become increasingly more complex
Just be scared like the media wants you to be.
European intelligence sources have told The Independent on Sunday they are "extremely concerned" that a number of North African terror cells linked to al-Qa'ida are active in London and other European cities and plotting attacks.
NOT TO WORRY.......
Britain and the European Commun-ity require a two weeks waiting period and official license to make exotic poisons.
(This just can't happen!)
/sarcasm?