Sarin exposure happens in all sorts of ways. You might breathe it, eat it on contaminated food or drink it in poisoned water. Your skin, especially mucus membranes like those around your eyes, may absorb it. Sarin is most commonly dispersed as an aerosol so that victims breathe it.
Depending on the amount of sarin you're exposed to, symptoms may vary. Typical telltale signs include constricted pupils, runny nose, drooling, watery eyes, headache, weakness, change in heart rate and vomiting.
It takes very little sarin before exposure becomes evident. A lethal dose via skin absorption may be as minuscule as a few droplets. Death can occur in less than a quarter of an hour. A massive dose can kill in just one minute. A milder level of exposure may not manifest itself through symptoms until nearly 20 hours later.
A lower exposure may not cause death, but victims may experience neurological problems for weeks after the event. Unluckier people may suffer permanent health problems, possibly to their respiratory or nervous systems.
If a person is fortunate enough to survive for more than a few minutes, there are antidotes available. Two antidotes are atropine and pralidoxime chloride. The latter must be administered within a few hours following exposure or it does very little good. Neither antidote is effective if they are given prior to sarin exposure.
Preventing exposure means wearing all-compassing personal protective equipment (PPE). So in areas where sarin is anticipated, people must wear a chemical, biological, radiological and nuclear (CBRN) suit paired with a self-contained breathing apparatus. That means you're covered from head to toe against the worst of the worst ... including sarin.