On November 30, 1992, future World Trade Center bomber Ramzi “Yousef, also using the name ‘Kamal Ibraham,’ one of 11 aliases he used during his six months in the US, began ordering chemicals from a local firm called City Chemical, including 1,000lbs (454kg) of urea, 105 gallons of nitric acid, and 60 gallons of sulphuric acid. Yousef told City Chemical’s salesman he knew exactly what he wanted: the nitrogen content of the urea crystals had to be 46.65 per cent and the sulphuric acid had to be 93 per cent pure. Yousef paid $3,615 in cash and arranged for the chemicals to be delivered to the storage shed [in New Jersey].”

 – Simon Reeve, The New Jackals, Page 146