Frequently Asked Questions About Biological and Chemical Agents

Medically Reviewed by Tyler Wheeler, MD on August 23, 2021
4 min read

The differences between biological and chemical weapons lie in their makeup, dissemination, and effects. Here are some typical differences between the two. Remember, though, any effects depend on the specific agents used.

Biological Agents

Chemical Agents

Natural origin

Man-made

Difficult, costly, small-scale production

Large-scale, cheaper, industrial production

Odorless and tasteless

Many have noticeable odor or taste. One exception is sarin gas, which is both odorless and tasteless.

Disseminated as aerosols in air or in water or food

Disseminated as aerosols or liquids

Most won't penetrate skin

Can penetrate skin

Delayed onset of physical effects

Oftem has immediate physical effects

Crisis measured in weeks, months

Crisis typically measured in hours, days

Delayed response that would build

Immediate, large response for some agents. Delayed for others.

Chemicals that are closely related to chemical weapons do have legitimate uses. Some nerve agents, for example, are similar to some insecticides and to medications that treat the disease myasthenia gravis. A byproduct of sulfur mustard is a long-time cancer chemotherapy drug. Chlorine and phosgene are also common industrial compounds.

The 1993 Chemical Weapons Convention bans the use, production, stockpiling, or acquisition of chemical weapons, requires the elimination of current stockpiles, and allows verification inspections. The United States and 191 other countries have agreed to the treaty.

The 1972 Biological and Toxins Weapons Convention bans the use, production, stockpiling, or acquisition of biological weapons. It does allow research with agents for vaccines or defensive purposes. The treaty does not include formal verification, so its effectiveness is limited. The United States and 177 other countries have agreed to it.

Antibiotics are prescription drugs that should be taken only under a doctor's advice. No one antibiotic can protect against all types of biological weapons -- or against all diseases. And holding on to antibiotics isn't a good idea because they'll expire eventually and become ineffective.

Gas masks do not provide protection unless you are wearing one at the exact moment of an attack with chemical or biological weapons. It's obviously impractical to wear a gas mask all the time. Besides, to work effectively, masks must be fitted to the wearer, who must be trained how to use them -- such as members of the military. Gas masks available for retail sale aren't guaranteed to work. There's also the possibility of accidental suffocation from wearing a mask incorrectly.

No. Anthrax and smallpox vaccines are not available to the general public. Doctors and hospitals don't have vaccine supplies for these like they do for other viruses. They would be made available only in emergency situations and to those who would be most likely to be exposed.

The government has gathered enough smallpox vaccine for everyone in the U.S. in the event of a smallpox attack. No such supply is available for anthrax (only military personnel have been getting vaccinated against anthrax). And there currently is no vaccine available for the plague, but one is being developed. Antibiotics are the first line of defense against anthrax, the plague, and most other bacterial biological threats. Antidotes can treat those who have been exposed to some chemical agents.

The CDC's National Pharmaceutical Stockpile Program sets aside a large supply of antibiotics, chemical antidotes, and other supplies in case of emergency. The goal is to send materials within 12 hours of notification to any U.S. location in the event of a terrorist attack with a biological or chemical agent. The program is a backup to local response and is deployed upon request by the states. The federal government has made arrangements with pharmaceutical companies to make large amounts of additional emergency supplies.