p-Aminobenzoic acid

Synonyms

1-Amino-4-carboxybenzene; 4-Aminobenzoic acid; 4-Carboxyaniline; Acido p-aminobenzoico [Italian]; Acidum paraminobenzoicum; Amben; Anti-chromotrichia factor; Anticanitic vitamin; Bacterial vitamin H1; Benzoic acid, 4-amino; Benzoic acid, 4-amino-; Benzoic acid, p-amino-; Chromotrichia factor; Hachemina; Kyselina p-aminobenzoova [Czech]; PAB; PABA; Pabacyd; Pabafilm; Pabamine; Papacidum; Paraminol; Paranate; Potaba; RVPaba Lipstick; Romavit; Rvpaba; Sunbrella; Super Shade by Coppertone; Trichochromogenic factor; Vitamin BX; Vitamin H'; p-Carboxyaniline; p-Carboxyphenylamine; para-Aminobenzoic acid; [ChemIDplus]

Category

Sunscreens

Description

Light beige, odorless solid; pure form is white; discolor on exposure to light and air; [Hawley] White crystalline solid; [MSDSonline]

Sources/Uses

Used to make local anesthetics, folic acid, and azo dyes; Also used in feed additives, sunscreens, and medications; [HSDB] Occurs naturally as B complex factor--about 10-100 ppm in brewer's yeast;

Comments

Oral LD50 = 1000 mg/kg (dog), 1830 mg/kg (rabbit), and 6000 mg/kg (rat); Causes acute hepatic necrosis in dogs given 2-3 g/kg; [HSDB] May cause irritation; May induce methemoglobinemia; [MSDSonline] May cause allergic dermatitis when applied as a sunscreen; No skin sensitization reported in occupational setting; [AIHA] "Patients may be allergic or photoallergic to PABA. If photoallergic, they may not react to PABA alone, but only with sun exposure." [Marks, p. 212]

Biomedical References

0.000278 mm Hg

5 mg/m3

Yes

MetHgb is secondary toxic effect

Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion

PACD (photoallergic contact dermatitis)

Not classifiable

Diseases

Occupational diseases associated with exposure to this agent:

• Contact dermatitis, allergic
• Contact dermatitis, photoallergic

Processes

Industrial Processes with risk of exposure:

• Farming (Feed Additives)