Some xylene data interesting is p-xylene melting point .Originaly i was searching for water soluability and toxicity.With this data will be maybe possible use citric acid wash directly orally and avoid possibe NaOH issues (test xylene with water and way how to get below smell threshold and after it taste threshold idealy without need of water reduction. Im ok with 1mg/L in oral dose .)
Property o-xylene m-xylene p-xylene
Melting point (°C) -25 -48 13
Water solubility at 20 °C (mg/litre) o-175 m-160 p-198 (25 °C)
The lowest xylene concentrations in air reported to be perceptible to humans range from 0.6
to 16 mg/m3
(3,4). The odour threshold for xylene isomers in water is 0.02–1.8 mg/litre (4,5).
Concentrations of 0.3–1.0 mg/litre in water produce a detectable taste and odour (6).
. A small part (< 5%) of the absorbed
amount is exhaled unchanged; the remainder is converted almost quantitatively to methyl
benzoic acid, which is excreted in urine as methyl hippuric acid. Few data on rates of
excretion are available; it is eliminated from subcutaneous fat in humans with a half-life
ranging from 25 to 128 h
Acute exposure
Xylene isomers have a low acute toxicity via the oral route; LD50s in rats range from 3.6 to
5.8 g/kg of body weight (1).
Short-term exposure
Available short-term oral studies are of limited design. The toxicological significance of the
ultrastructural liver changes observed in rats (24) at the only dose level tested (200 mg of oxylene per kg of feed) is questionable given the absence of any histopathological signs in the
livers of rats tested at much higher dose levels in oral studies carried out under the US
National Toxicology Program (25). In addition, the results of the single-dose study are
presented only for the group of methylated benzenes tested; the results observed with the
individual compounds are not reported. In inhalation studies in rats, liver enzyme induction
was observed at concentrations of 217 mg/m3 and above, 6 h per day (NOAEL not
determined) (23,26).
Long-term exposure
A carcinogenicity study in rats and mice provided some relevant information on the toxic
effects of xylenes after oral administration. In rats, 0, 250, or 500 mg/kg of body weight per
day was administered by gavage in corn oil, 5 days per week for 103 weeks. Growth was
decreased at 500 mg/kg of body weight per day; no compound-related histological lesions
were observed. The NOAEL for rats was 250 mg/kg of body weight per day. In mice, the
dose levels tested were 0, 500, and 1000 mg/kg of body weight per day. The only observed
effect in this species was hyperactivity at 1000 mg/kg of body weight per day (25).
Reproductive toxicity, embryotoxicity, and teratogenicity
Both of the oral studies carried out in mice showed maternal toxicity with concurrent
embryotoxicity and teratogenicity (increased incidence of cleft palate) at the higher dose
levels tested (LOAEL 640 mg/kg of body weight; NOAEL 255 mg/kg of body weight)
(27,2
. Teratogenicity studies carried out in rats and mice by the inhalation route showed
maternal toxicity at high dose levels but no teratogenicity (7,23).
Mutagenicity and related end-points
The mutagenic activity of xylenes was examined in bacteria and in mammalian cells (both in
vitro and in vivo) with negative results. The significance of a weak positive effect observed
with technical xylene in a Drosophila recessive lethal test is not clear, given the negative
results in the same test system obtained with the individual components of the technical
mixture (7,23,29).
Carcinogenicity
An oral carcinogenicity study in rats (0, 250, or 500 mg/kg of body weight per day
administered by gavage in corn oil, 5 days per week for 103 weeks) and mice (0, 500, or 1000
mg/kg of body weight per day) did not show xylenes to be carcinogenic (25).