The three cresols, o-cresol, m-cresol and p-cresol make up the major components in cresylic acid. These products are typically labeled highly toxic or toxic, are readily absorbed through the skin and considered combustible liquids.
In addition to production at DGC, cresols are a natural product of metabolite processes and therefore found in the environment. The annual amount of cresols ending up on cow pastures of the world from cattle urine exceeds the world's total industrial capacity to manufacture. Dilute cresols can be found in streams and rivers from rotting leaves, in teas, in whiskey, in wine and in cheese. Even if your diet contains none of these, cresols can be found in human urine as a natural metabolic product. Cresols are substances which are ubiquitous in the environment and in mammalian life.
The OSHA PEL or exposure limit for cresols in air is 5 PPM. These are not highly volatile substances. The boiling point temperature at which the substances give off their most vapors ranges from 375F to 397F. These substances have low evaporation rates at normal temperatures. It is highly recommended to avoid breathing cresol vapors. Cresylic acid is a dark brown liquid with a phenolic odor (sweet, tarry) with a typical odor thresold of 2.8 parts per billion (ppb) giving it good warning properties. Vapors are heavier than air with a vapor density of 3.7 compared to air at 1.0.
Material is considered extremely destructive to the mucous membranes of the upper respiratory tract. Inhalation may result in spasm, inflammation and edema of the larynx and bronchi, chemical pneumonitis and pulmonary edema. Symptoms of exposure may include a burning sensation, coughing, wheezing, laryngitis, shortness of breath, headache, nausea and vomiting. Material is extremely destructive to tissue of the eyes and skin, having a strong corrosive effect.
It is rapidly absorbed through the skin and is capable of causing death if enough body surface is contacted.
Chronic, long term exposure in the workplace is a potential source of concern. Although a person is able to metabolize and excrete small amounts of absorbed cresols, exposure day in and day out to levels exceeding the OSHA PEL may eventually lead to renal, CNS, liver, pancreas, spleen and cardiovascular damage.