m-Cresol - ipcs inchem

OECD SIDS
m- / p-CRESOL
and reduced body weights, increases in liver and kidney weights) (NOAEL, fertility and general
toxicity: 0.25 % in feed (ca. 375 mg/kg bw/day).
In developmental toxicity studies with m-cresol in rats and rabbits, no toxic effects on the
developing organism could be found despite of the toxic effects on the dams as evidenced by
hypoactivity, ataxia, tremor, twitches, prone positioning, audible respiration, perioral wetness, and a
reduction in food consumption in rats, and audible respiration, and ocular discharge in rabbits
(NOAELs: 175 mg/kg bw (maternal toxicity) and 450 mg/kg bw (developmental toxicity) for rats,
and 5 mg/kg bw (maternal toxicity) and 100 mg/kg bw (developmental toxicity) for rabbits,
respectively. p-Cresol caused fetotoxicity (delayed ossification, decreased fetal body weight) at
maternally toxic dose levels in rats, but not in rabbits (NOAEL, rat, maternal toxicity,
developmental toxicty: 175 mg/kg bw/day). Based on the available data, it can be assumed that
m/p-cresol mixtures may have the potential to induce fetotoxicity in the presence of maternal
toxicity.
In humans, the accidental oral uptake of cresols can induced irritation of mouth and throat,
abdominal pains, vomiting, haemolytic anemia, increased heart rate, liver and kidney damage,
headaches, facial paralysis, drowsiness, cramps, coma and death. Skin contact with cresols can
result in corrosion, skin depigmentation, effects on the nervous system, liver and kidneys,
gastrointestinal bleeding, and can cause human fatalities.
There are some case reports about tumour development in connection with probable exposure
against cresol isomers. Since co-exposures to other substances cannot be excluded, no conclusion
on a carcinogenic potential can be deduced from these case reports.
4 HAZARDS TO THE ENVIRONMENT
4.1 Aquatic Effects
For the effects assessment of cresols on aquatic organisms their ready biodegradability in aqueous
solutions has to be taken into account. In static tests with analytical monitoring Falk-Petersen et al.
(1985) found less than 10 % loss of the test substance after 4 days, thus short term tests without
analytical monitoring can be accepted as valid.
Fish
Valid tests on acute toxicity to fish are available for 14 freshwater and 1 marine species. An
overview is presented in table 4.1.
A flow-through test on the acute toxicity of p-cresol to Pimephales promelas was conducted by
Geiger et al. (1986). The fish were exposed in Lake Superior water to 5 test substance
concentrations. Analytical measurements revealed that the cresol concentrations were stable during
the test period. Based on measured concentrations a 96h-LC50 of 16.5 mg/l was obtained. The
affected fish lost schooling behaviour, swam near the tank surface, were hyperactive and
overreactive to external stimuli, they had increased respiration and lost equilibrium prior to death.
DeGraeve et al. (1980) conducted flow-through bioassays on the toxicity of m- and p-cresol to
Pimephales promelas and Oncorhynchus mykiss. The fish were exposed in well-water to 7
concentrations of the test substances and one control. O. mykiss was the more sensitive species with
LC50 values of 8.9 mg/l for m-cresol and 7.9 mg/l for p-cresol; the LC50 values for P. promelas
were 55.9 mg/l for m-cresol and 28.6 mg/l for p-cresol. All effect values are based on measured
concentrations.
UNEP PUBLICATIONS 35