Given the ubiquity and volume of chlorine in industrial and commercial locations, widespread exposures could occur from an accidental spill or release, or from a deliberate terrorist attack.
Because chlorine is a gas at room temperature,
exposure occurs via inhalation. People may also be exposed to
chlorine through skin or eye contact, or through ingestion of
chlorine-contaminated food or water.
The extent of poisoning caused by chlorine depends on the amount
of chlorine a person is exposed to, how the person was exposed,
and the length of time of the exposure.
When chlorine gas comes into contact with moist tissues such as
the eyes, throat, and lungs, an acid is produced that can damage
these tissues.
Immediate signs and symptoms of chlorine exposure
During or immediately after exposure to dangerous concentrations of chlorine, the following signs and symptoms may develop:
- Coughing
- Chest tightness
- Burning sensation in the nose, throat, and eyes
- Watery eyes
- Blurred vision
- Nausea and vomiting
- Burning pain, redness, and blisters on the skin if exposed to gas, skin injury similar to frostbite if exposed to liquid chlorine
- Difficulty breathing or shortness of breath (may appear immediately if high concentrations of chlorine gas are inhaled, or may be delayed if low concentrations of chlorine gas are inhaled)
- Fluid in the lungs (pulmonary edema) within 2 to 4 hours

Apex, NC Hazardous Materials Fire Causes Evacuations. Read About the
Incident and Possible Health Effects,
Chlorine
has been identified by the Environmental Protection Agency (EPA) and The
Agency for Toxic Substances and Disease Registry (ATSDR) as one of the most
commonly found substances at hazardous waste sites on the "National
Priorities List" (NPL). The NPL is comprised of 1,300 of the most hazardous
waste sites in the nation, which have been targeted for long-term federal
cleanup activities. In addition, chlorine has also been identified by EPA
and ATSDR as a substance which poses a significant potential threat to human
health. (Source: Priority List of Hazardous Substances, ATSDR, Atlanta GA)