The Postal Service™ is reminding customers and employees that metallic mercury (also known as elemental mercury) and devices containing metallic mercury are prohibited in the mail stream. This includes antique items such as thermometers, barometers, and blood pressure monitors and similar devices. Due to the nature of mercury and its capacity to induce toxic reactions when inhaled or exposed to the skin, mercury represents a tremendous safety risk to our employees and customers.
When mercury spills it breaks into droplets and the droplets spread and build up in tiny cracks and spaces. Mercury can be absorbed or be drawn into carpet, furniture, floors, or walls, and can be tracked throughout buildings and vehicles if not cleaned up right away. When spilled, Mercury can vaporize (evaporate) into the air and get into the ventilation system ultimately spreading throughout buildings and vehicles. The vapor is very dangerous because it cannot be seen or smelled. If the spill occurs in a hot location (vehicle cargo area), it will vaporize more quickly and can be more dangerous.
Short-term exposure to high levels of mercury vapors include:
n Headache.
n Cough, sore throat.
n Eye irritation.
n Changes in vision.
n Chest pain.
n Increase in blood pressure or heart rate.
n Nausea, vomiting, or diarrhea.
Health effects caused by long-term exposure to mercury vapors include:
n Anxiety.
n Tremors.
n Forgetfulness.
n Changes in hearing.
n Excessive shyness.
n Anorexia.
n Irritability.
n Sleeping issues.
n Loss of appetite.
n Changes in vision.
It is for these reasons that elemental mercury is prohibited from the mail (Reference Publication 52, Hazardous, Restricted, and Perishable Mail, section 348.21 and appendix A.)
Mercury in manufactured articles, identified as UN3506, such as compact fluorescent lamps and similar consumer devices containing minute amounts of mercury, are mailable domestically but not internationally (including APO, FPO, and DPO destinations). Each device, article, or apparatus must contain 100 milligrams (mg) (0.0035 ounce) or less of mercury (less than a grain of salt) and each mailpiece must contain no more than 1 gram (g) (0.035 ounce) of mercury. Mercury in devices categorized under UN3506 typically exists in a vaporized state — no metallic mercury will be visible in UN3506 devices.
