Morpholinium toluene-4-sulphonate

Endpoint summary

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

7 500 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Acute oral toxicity

An acute oral toxicity study was performed with the test compound Morpholinium-toluene-4-sulphonate (Haerter 527) (BASF SE, 1976). Male and female Sprague-Dawley rats received 68.1 % and 100 % (v/v) aqueous solution of Morpholinium-o/p-toluolsuIfonat by gavage. No deaths occurred at 68 % and 1/10 animals died at 100 %. Therefore, the LD50 was set at higher than 100 % (> 10000 µl/kg). Since the test substance was applied as a 75 % solution, an LD50 value of 7500 µl/kg (=7500 mg/kg) can be calculated.

This assessment is supported by the acute toxicity studies conducted with the read-across chemicals (please refer to the read-across statement/data matrix in section 13).

In a supporting GLP guideline study, male and female rats were exposed by oral gavage to toluene-4-sulphonic acid (CAS No, 104-15-4) (Habrinol Decin s.r.o., 1988). The LD50 value was 1410 mg/kg bw.

In a further supporting acute oral toxicity study, benzenesulphonic acid (CAS No. 98-11-3) was tested in male Carworth-Wistar rats (Smythe et al., 1962). A logarithmic series of single doses was applied and the LD50 value was set at > 0.89 (0.36 - 3.21) ml/kg bw which is equivalent to 1104 mg/kg.

In addition, xylenesulphonic acid (CAS No. 25321-41-9) was tested in Sprague-Dawley rats by oral gavage (Huntsman, 1977). Applied doses were in the pilot study 15, 5, 0.5, 0.05 and 0.001 g/kg and in the main study 0.51 g/kg. Rats dosed at 15 and 5 g/kg died within 24 hours and 3/10 animals at 0.51 g/kg died at day 2 and 5. The LD50 was between 510 and 5000 mg/kg.

Two further studies performed with benzenesulfonic acid in mice and rats (CAS 1333-39-7) resulted in LD50 values of > 1500 mg/kg and > 1900 mg/kg, respectively (Lewis, 1996 a and b).

A further supporting study was performed with morpholine (CAS 110-91-8). Here, an LD50 value of ca. 1900 mg/kg was received.

This confirms the generally low acute oral toxicity hazard of the salt Morpholinium-toluene-4-sulphonate and its dissociation products.

 

Acute inhalation toxicity

An acute inhalation hazard test was performed with Morpholinium-toluene-4-sulphonate (BASF, 1976). Male and female rats were exposed to a saturated vapour atmosphere with a calculated concentration of 5.84 mg/L. No mortality occurred but a slight irritation of the respiratory mucosa was detected. Thus, inhalation of a concentrated vapour of the test item did not pose an acute risk to animal's health.

In two further studies, rats were exposed to a highly saturated vapour-air-mixture enriched with the volatile components of the source chemicals benzenesulfonic acid (Smythe, 1962) or morpholine (BASF AG, 1967). Benzenesulfonic acid lead to a mortality of 3/6 animals after 8 hours of exposure. Morpholine resulted in a mortality of 2/6 and 6/6 animals after 3 hours and 5.5 hours, respectively, mainly driven by the corrosive properties of morpholine.

The corrosive properties of the might trigger the irritant response observed for Morpholinium-toluene-4-sulphonate.

Acute dermal toxicity

There are no data available for acute dermal toxicity of Morpholinium-toluene-4-sulphonate. But studies are available for the read-across chemicals.

The aromatic sulphonic acids are corrosive and therefore with regard to animal welfare, dermal studies are not recommended but there are dermal acute toxicity studies for the closely related hydrotropes. Hydrotropes are the salts of the sulphonic acids with no corrosive properties. The dermal LD50 for the hydrotropes is >2000 mg/kg based on studies with 4 of the salts.

The first study was conducted with sodium cumene sulphonate (CAS No. 28348-53-0) equivalent to OECD 402 (Procter and Gamble Company, 1968). Six rabbits (3 with shaved and abraded skin and 3 with intact shaved skin) were exposed in a limit test to 2000 mg/kg bw. There were no deaths but primary irritation was reported at the site of exposure. The dermal LD50 is higher than 2000 mg/kg.

In a GLP-guideline study performed with calcium xylene sulphonate, New Zealand White rabbits received 2000 mg/kg test item under occlusive conditions. The dermal LD50 was >2000 mg/kg (Ruetgers-Nease Chemical, Inc, 1994).

In an acute dermal toxicity test performed with ammonium xylene sulphonate, New Zealand White rabbits were treated for 24 hours under occlusive conditions with 500 mg/kg and 2000 mg/kg of the test item. No mortalities occurred and the LD50 value was set at > 2000 mg/kg (Sasol, 1980). Same result was received for a study conducted with sodium xylene sulphonate. Here, an LD50 value higher than 2000 mg/kg was reported (Sasol, 1981).

Morpholine was tested similar to OECD 402 (Smyth et al., 1954) in New Zealand White rabbits with concentrations up to 20 ml/kg. Mortality occurred within 14 days. Morpholine has strong corrosive properties but no information was given on the condition of the skin and its possible connection to the occurring mortalities. The LD50 was set at 500 mg/kg (0.5 mL/kg).

As Morpholinium-toluene-4-sulphonate is a salt, data received from the hydrotopes do better reflect the possible acute dermal toxicity compared to the corroding morpholine. For that reason, Morpholinium-toluene-4-sulphonate is expected to have a low dermal toxicity.

Justification for classification or non-classification

Based on the available data, no classification is proposed.