Health Effects

Ammonia is not, strictly speaking, a poison and repeated exposure to it produces no additive (chronic) effects on the human body. However, even in small concentrations in the air it can be extremely irritating to the eyes, throat, and breathing passages.

Anhydrous ammonia primarily affects three areas of the body:

• Eyes
• Lungs
• Skin

Eyes

Everything from mild irritation to destruction of the eye can occur depending on whether a spray or gas is involved. Ammonia penetrates the eye more rapidly than other alkalis.

Lungs

In the lungs, liquid anhydrous ammonia causes destruction of delicate respiratory tissue. Exposure to ammonia vapor may cause:

• Convulsive coughing.
• Difficult or painful breathing.
• Pulmonary congestion.
• Death.

Skin

Skin damage depends upon the length and concentration of exposure and can range from mild irritation, to a darkened freeze-dry burn, to tissue destruction. Because liquid ammonia boils at -28°F, the expanding gas has the potential to freeze anything in its path of release, including human flesh and organs.

Because water can absorb ammonia so readily, it is a factor that contributes to human toxicity. Ammonia will keep spreading across contacted skin until the chemical is diluted by skin moisture.

Alkalis effect tissue differently than acids, which tend to burn and seal off a wound. Alkalis, such as ammonia cause liquidization of tissue and turn tissue into a sticky "goo" and mix with this tissue, causing further damage. As a result, anhydrous ammonia burns keep spreading until the chemical is diluted.

In addition to liquidization, super-cooled anhydrous ammonia spray causes a freeze dry effect like frost bite when it hits the skin. The spray is also capable of freezing clothing to skin so that if the clothing is removed incorrectly whole sections of skin can be torn off.

High concentrations in the air can also dissolve in the moisture of the skin or perspiration and result in a corrosive action on the skin and mucous membranes.

First Aid

Decontaminate the victim as quickly as possible.

• First, flush the eyes with clean water. Then flush the whole body or the exposed area with generous amounts of water; includes the hair, ears, under chin, and armpits. Any water source is acceptable; such as showers, hoses, or stock tanks.
• Remove contaminated clothing, but only after careful flushing and warming to prevent the previously mentioned problem of skin sticking to the clothing.

To learn more about Ammonia Refrigeration visit our Ammonia Refrigeration Safety Online Training web page.