2,6-xylidine

Endpoint summary

Description of key information

Acute Oral toxicity
Rat: 	LD50 = 1270 (940-2140) mg/kg bw (females, Montgomery et al. 1982)
	LD50 = 1160 (830-1630) mg/kg bw (females, Montgomery et al. 1982)
       	LD50 = 1310 mg/kg bw (males, Montgomery et al. 1982)
	LD50 = 840 (640-1120) mg/kg bw (males, Jacobson 1972)
                        LD50 = 1230 (890-1700) mg/kg bw (males, Vernot et al. 1977) 
                        LD50 = 2040 mg/kg bw (Lindstrom et al. 1969)
                        LD50 = 300-2000 mg/kg bw (female, JECD, Val. 4)
Mouse:	LD50 = 1160 (790-1710) mg/kg bw (males/females, Montgomery et al. 1982)
Acute Inhalation toxicity
Rat: 	IHT: 7h: LC50 >0.75 mg/l air, no mortality in a saturated vapour atmosphere (BASF 1982) 
Acute Dermal toxicity
No studies or results are available.

Additional information

There are only limited valid data available for the assessment of the acute toxicity of 2,6-xylidine.

 

Oral

Data an acute toxicity from various studies are listed in the section above. An acute toxicity study comparable to OECD guideline 401, groups of 10 male and 10 female rats were exposed to doses up to 5000 mg/kg bw. The only observed clinical signs of toxicity were slightly reduced behavioural state and signs of eye irritation. All animals survived doses up to 680 mg/kg bw (females) and 1000 mg/kg bw (males). Necropsy findings included signs of organ toxicity in livers, kidneys and lungs (Montgomery et al. 1982). Clinical symptoms and signs of toxicity observed by other investigators included mainly cyanosis (bluish coloration of lower limbs and of mouth and nose) (Jacobson et al.) and signs of methaemoglobinemia.

 

Inhalation

In an inhalation hazard test) 6 rats were exposed to a saturated vapour of 2,6-xylidine (0.75 mg/l air). At this concentration clinical signs observed included salivation, aqueous eye secretion and muzzles wiping during the exposure and salivation, apathy, closed eyes and slight secretion of the nose up to several hours after exposure; all effects reversible within 1day. Mortalities did not occur and no pathological abnormalities were detected in post mortem necropsy (BASF AG).

 

Dermal

Up to date there is no information available concerning the acute dermal toxicity of 2,6-xylidine.

 

In general, available data for 2,6-xylidine show a wide range of observed acute oral toxicity with LD₅₀ values ranging from about 600 to 2000 mg/kg bw involving liver, lung and kidneys as the target sites of acute toxicity. Whether interlaboratory or individual variations among the different rat strains are responsible for the great variety of acute LD₅₀ remains elusive.

As an aromatic amine 2,6-xylidine is able to form methemoglobinemia. The limit dose of 200 mg/kg caused moderate MetHb (approx.30%) after 4 hours. Thus, also with respect to the methemoglobinemia-forming potential "harmful" is the appropriate classification. There are no LC50 determinations; yet from an inhalation hazard test with no deaths in highly enriched or saturated vapor atmosphere the risk of inhaling high vapor concentrations seems

to be low.

Justification for classification or non-classification

Based on the criteria laid down in the GHS and considering the different results of the individual studies the test substance has to be classified in category 4 for oral exposure. Since an inhalation hazard test with rats exposed to 0.75 mg/l air for 7 hours did not result in any mortalities and only transient clinical signs or signs of respiratory irritation, there is no indication given to classify the substance according to EU or GHS requirements for its acute inhalative toxicity. For dermal exposure there is no reliable information available to classify the test substance according to the criteria laid down by the EU or GHS.

In addition the test substance is listed in the CLP Regulation No 1272-2008 on classification, labelling and packaging CLP of substances and mixtures and classified as acute toxic by oral, dermal and inhalative exposure (GHS cat. 4).