CHAPTER 2-126: PHENOL AND RELATED COMPOUNDS

INTRODUCTION

Phenol (carbolic acid) was introduced into household use as a potent germicidal agent but today is found in fewer products because less toxic compounds have replaced it. Phenol can be found in topical skin products (eg, Campho-phenique containing 4.7% phenol) and in surface deodorizers and disinfectants (eg, Creolin^®). Phenol is used in the production of fertilizers, wood preservatives, paint removers, and other chemicals. Hexachlorophene is a chlorinated biphenol that was used widely as a topical antiseptic and preoperative scrub until its adverse neurologic effects were recognized. Other phenolic compounds include creosote, creosol, cresol, cresylic acid, hydroquinone, eugenol, and chloroxylenol, the active ingredient in Dettol^®. Pentachlorophenol and dinitrophenols are discussed

MECHANISM OF TOXICITY

Phenol denatures protein, disrupts the cell wall, and produces a coagulative tissue necrosis. It may cause corrosive injury to the eyes, skin, and respiratory tract. Systemic absorption may result in cardiac arrhythmias and CNS stimulation, but the mechanisms of these effects are not known. Some phenolic compounds (eg, dinitrophenol and hydroquinone) may induce hemolysis and methemoglobinemia.

TOXIC DOSE

The minimum toxic and lethal doses are not well defined. Most phenolic compounds can be absorbed following inhalation, skin exposure, and ingestion.

1. Inhalation. The OSHA recommended workplace permissible exposure limit for pure phenol is 5 ppm (19 mg/m³) as an 8-hour time-weighted average. The level considered immediately dangerous to life or health (IDLH) is 250 ppm.

2. Skin application. Death has occurred in infants from repeated dermal applications of small doses. A 9-year-old child developed brief runs of ventricular tachycardia, became obtunded and required intubation after application of Creolin^® to her head and upper torso. Cardiac arrhythmias occurred after dermal application of 3 mL of an 88% phenol solution. Solutions of more than 5% can be corrosive.

3. Ingestion. Deaths have occurred after adult ingestions of 1–32 g of phenol; however, survival after ingestion of 45–65 g has been reported. As little as 50– 500 mg has been reported as fatal in infants.

4. Pharmacokinetics. Phenol is rapidly absorbed by all routes. Its elimination half-life is 0.5–4.5 hours.

CLINICAL PRESENTATION

Toxicity may result from inhalation, skin or eye exposure, or ingestion.

1. Inhalation. Vapors from phenol may cause respiratory tract irritation and chemical pneumonia. Smoking of clove cigarettes (clove oil contains the phenol derivative eugenol) may cause severe tracheobronchitis.

2. Skin and eyes. Dermal exposure may produce a deep white patch that turns red, after which the skin stains brown. This lesion is often initially painless. Irritation and severe corneal damage may occur if concentrated phenolic compounds come in contact with eyes.

3. Ingestion usually causes vomiting and diarrhea, and diffuse corrosive GI tract injury may occur. Systemic absorption may cause a mild transaminitis, agitation, confusion, seizures, coma, hypotension, arrhythmias, and respiratory arrest.

4. Injection. Accidental injection of high concentrations ...