Toxicological Evaluation and Limit Values for Nonylphenol, Nonylphenol Ethoxylates, Tricresyl, Phosphates and Benzoic Acid

3. Human toxicity

3. Human toxicity
3.1 Short term toxicity
3.2 Long term toxicity
3.3 Reproductive and Developmental effects
3.4 Mutagenic and genotoxic effects
3.5 Carcinogenic effects

TCP with at least one o-cresyl ring produce organophosphorous induced delayed neuropathy (OPIDN) in humans. The symptoms of OPIDN are sharp, cramp like pains in the calves, and some numbness and tingling in the feet, and sometimes hands. Within a few hours or a day or two at most these pains are followed by increasing weakness of the lower limbs, and soon after the patient becomes unsteady and then unable to keep his balance. One or two weeks after the onset in the lower limbs, and while paralysis may still be progressing, weakness spreads to the hands. While some patients show complete wrist drop and total loss of power in the hands, sometimes with weakness up to the elbows, the predominant neurological abnormalities are observed in the lower limbs, where bilateral drop foot with complete loss of power from the ankle down is a common finding. (Inoue et al. 1988).

Inhalation

No relevant data available

Oral intake

In Sri Lanka, acute polyneuropathy resulting in some cases of OPIDN (numbers not specified) occurred in over 20 young women in 1977 to 1978. The cause was a special cooking oil, gingili oil, contaminated by TCP. The chemical composition of the TCP mixture was stated to be an isomeric mixture of tricresyl phosphate with little or no o-TCP. The amount of other ortho isomers was not stated. The special use of this cooking oil, only taken in an egg shell daily for two weeks after the first menstrual flow, allows a daily intake of 5-10 mg TCP/kg b.w./day to be estimated. (Senanayake & Jeyaratnam 1981).

According to Staehelin (1941), a single dose of 0.15 g o-TCP can produce toxic symptoms (type not indicated). According to Inoue et al. (1988) severe neurological disturbance developed in three men after oral intake of 0.5 to 0.7 g o-TCP in a Swiss incident of o-TCP poisoning. It has been suggested that individual susceptibility varies greatly (Inoue et al. 1988).

Several incidents of TCP poisoning resulting in OPIDN, involving from a few (6) to 50,000 people have been reported in the literature following oral intake of TCP (see EHC 1990) but none of them allows estimation of the daily intake. A recent study, which allows estimation of daily intake, will be described below. This is not included in the EHC review.

In 1990, in China 176 people became intoxicated by TCP, containing 20% o-TCP, from flour from the local mill. The TCP was in the machine oil used to lubricate the mill, and the lubricant leaked into the flour. In all, there were 91 cases of TCP intoxication with diagnosed clear OPIDN and 85 cases with mild nausea and weakness. Twelve persons were hospitalised and after two years 9 of the 12 were still unable to walk. Flour from the mill and the households were sampled and analysed for TCP and was found to contain 0.046 to 0.181 mg TCP/g flour. An average daily dose over 10 to 46 days was calculated to be 47.5 to 76 mg TCP. (Wang & Tao 1995).

Among two patients, who had developed allergic contact dermatitis to adhesive bandages, and who were patch tested for the chemicals contained in the adhesive bandage, one patient responded positive to tricresyl phosphate (isomer not stated) (Norris and Storrs 1990).

At least five cases of OPIDN have been described after occupational exposure to o-TCP or TCP. In some of the cases, dermal contact was suggested to be the route of exposure. (EHC 1990).

No relevant data have been found.

No data have been found.

3.5 Carcinogenic effects

No data have been found.