Para-aminobenzoic acid (PABA) is naturally occurring substance. Because it can absorb ultraviolet (UV) light, it is often used in sunscreen products. PABA is sometimes called vitamin Bx, but it is not a true vitamin.

This article discusses reactions due to PABA overdoses and allergic responses.

Para-aminobenzoic acid (also known as 4-aminobenzoic acid)

PABA is used in certain sunscreen and skin care products.

It may also naturally occur in the following products:

• Brewer's yeast
• Liver
• Molasses
• Mushrooms
• Spinach
• Whole grains

This list may not be all inclusive

• Coma
• Diarrhea
• Dizziness
• Eye irritation if it touches the eyes
• Fever
• Nausea
• Rash (allergic)
• Shortness of breath (more common in allergic reactions)
• Slowed breathing (in extremely high doses)
• Stupor
• Vomiting

NOTE: Most PABA reactions are due to allergic reactions, not overdoses.

Seek immediate medical help. DO NOT make a person throw up unless told to do so by Poison Control or a health care professional.

If the chemical is on the skin or in the eyes, flush with lots of water for at least 15 minutes.

Determine the following information:

• The patient's age, weight, and condition
• Name of product (as well as the ingredients and strength, if known)
• The time it was swallowed
• The amount swallowed

The National Poison Control Center (1-800-222-1222) can be called from anywhere in the United States. This national hotline number will let you talk to experts in poisoning. They will give you further instructions.

This is a free and confidential service. All local poison control centers in the United States use this national number. You should call if you have any questions about poisoning or poison prevention. It does NOT need to be an emergency. You can call for any reason, 24 hours a day, 7 days a week.

Take the container with you to the hospital, if possible.

See: Poison control center - emergency number

The health care provider will measure and monitor the patient's vital signs, including temperature, pulse, breathing rate, and blood pressure. Symptoms will be treated as appropriate. Specific treatment depends on the type of reaction or exposure. In general, the patient may receive:

• Activated charcoal
• Artificial respiration
• Fluids through a vein (IV)
• Endoscopy -- camera down the throat to see burns in the esophagus and the stomach
• Tube thru the nose into the stomach to empty the stomach (gastric lavage)
• Medicines for allergic reactions

Swallowing sunscreen products containing PABA rarely causes symptoms, except in very large doses. Some people may be allergic to PABA.