In addition to being grouped together as NBC's (nuclear, biological, chemical) under weapons of mass destruction, biological and chemical weapons have many similaries.
Biological and chemicals have many differences by virtue of their different categorizations. The following is a summary of their differences:
| Biological Weapons | Chemical Weapons | |
| Cause of death or injury | Disease | Poisoning |
| Victims | Some can spread beyond people who are initially affected. This outbreak of contagious disease is an epidemic. | Only those who come into contact with them |
| Ease of Manufacturing | Slightly more difficult because they involve sensitive living organisms | Slightly less difficult |
| Cost | Less expensive. A basic facility for biological weapons production can be constructed and operated for less than $10 million. A terrorist group with a competent team of graduate students could operate a small-scale program for a few hundred thousands dollars or less. | More expensive |
| Facilities for Production and Storage | Less space. A facility no larger than a few hundred square feet is required for a basic biological weapons program. | Much bigger space |
| Speed of Effects | Take time to develop | Almost instantaneous |
| When spread properly under ideal conditions, number of people killed | One biological weapon can kill 100 to 1000 times as many people compared to one chemical weapon of the same weight | One chemical weapon can kill 100 to 1000 times less people compared to one biological weapon of the same weight |
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