Morpholinium toluene-4-sulphonate

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Additional information

In several repeated dose studies performed with morpholine,toluene-4-sulphonic acid or its salts, no apparent adverse effects on reproductive organs were observed in rats (Conaway et al., 1984; Sander & Buerkle, 1969; Shibata, 1987, Habrinol Decin s.r.o.,Huntsman, 1969;The Soap and Detergent Association, 1979 and 1980). Exposure times ranges from 14-days to 13 weeks.

Because of a high correlation, histopathology data and organ weights from repeated dose studies were used to assess male fertility (Mangelsdorf, 2003). Here, these parameters, taken from 90 day studies, were in fact shown to be more sensitive than fertility parameters that were measured during multi-generation studies. It could also be shown that exposure for 4 weeks suffices for an assessment of male fertility, although 90 day studies have been regarded as superior in the past because they cover a complete cycle of spermatogenesis (Mangelsdorf, 2003). If such a 28 day study shows neither relevantly elevated testis or ovary weights nor histopathological alterations in those organs, the weight of the evidence is that effects on reproduction are also not expected (BAuA, 2003). A comparison of more than one hundred 90 day studies with two-generation studies that used the same test substance additionally showed that the NOAELs differed by less than the variation limit of studies, i.e. a factor of two (Janer, 2007).

Based on the argumentation of Mangelsdorf (2003), the information gained from a two-generation study can be regarded as minimal if a 90 day study has been performed. Thus, based on the data presented for morpholine, toluene-4-sulphonic acid or its salts, information gained from a two-generation study are regarded as not necessary with regard to the fact that REACH allows the assessment of the reproductive toxicity of a given chemical with the help of findings from studies with repeated administration. This is in line with the idea that the information requirements under REACH are regarded as the evaluation of endpoints which does not necessarily require data from specific studies.

Effects on developmental toxicity

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study according to OECD GL 414 (“Prenatal Developmental Toxicity Study”)

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Research Models and Services, Germany GmbH
- Age at study initiation: about 10-12 weeks
- Weight at study initiation: 143.5-197.9 g
- Fasting period before study: no data
- Housing: individually in type M III Makrolon cages supplied by BECKER & CO., Castrop-Rauxel, Germany
- Diet: ad libitum (ground Kliba maintenance diet mouse/rat “GLP”)
- Water: ad libitum (drinking water)
- Acclimation period:


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24 °C
- Humidity (%): 30 - 70 %
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: 05.11.2007 To: 20.11.2007

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
The test substance solutions were prepared at the beginning of the administration period and thereafter at intervals of 7 days, which took into account the analytical results of the stability verification. For the preparation of the solutions, appropriate amounts of the test substance were weighed
in a beaker, topped up with drinking water and subsequently thoroughly mixed using a magnetic stirrer.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analyses of the test substance preparations were carried out as a separate study compliance with the Principles of Good Laboratory
Practice at GKA Competence Center Analytics, BASF SE, Ludwigshafen, Germany. As analytical method .....

Samples of the test substance solutions were sent to the analytical laboratory twice during the study period for verification of the concentrations. Analytical verifications of the stability of the test substance in drinking water for a period of at least 7 days at room temperature were carried out before the study was initiated.

Details on mating procedure:

The animals were paired by the breeder (“time-mated”) and supplied on GD 0 (= detection of vaginal plug/sperm). The animals arrived on the same day (GD 0) at the experimental laboratory. The following day was designated as “GD 1”.

Duration of treatment / exposure:

Test substance was administered on gestation days (GD) 6 through 19.

Frequency of treatment:

The test substance solutions were administered to the animals orally by gavage, once a day, always at approx. the same time in the morning.
A standard dose volume of 10 mL/kg bw was used for each test group. At terminal sacrifice on GD 20, all females had implantation sites.

Remarks:

Doses / Concentrations:
75 mg/kg bw/day
Basis:
nominal conc.
low-dose level

Remarks:

Doses / Concentrations:
250 mg/kg bw/day
Basis:
nominal conc.
mid-dose level

Remarks:

Doses / Concentrations:
750 mg/kg bw/day
Basis:
nominal conc.
high-dose level

No. of animals per sex per dose:

25 female rats

Control animals:

yes, concurrent vehicle

Maternal examinations:

MORTALITY: Yes
- Twice a day on working days or once a day on Saturdays, Sundays or on public holidays (GD 0-20)

CAGE SIDE OBSERVATIONS/DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: at least once daily for any signs of morbidity, pertinent behavioral changes and signs of overt toxicity.
- Time schedule: If such signs occurred, the animals were examined several times daily (GD 0-20)

BODY WEIGHT: Yes
- Time schedule for examinations: GD 0, 1, 3, 6, 8, 10, 13, 15, 17, 19 and 20
- Furthermore, the corrected bw gain was calculated after terminal sacrifice (terminal bw on GD 20 minus weight of the unopened uterus minus bw on GD 6).

FOOD CONSUMPTION: Yes
- With the exception of day 0, the consumption of food was determined on the same days as bw

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organs examined: Liver, Kidneys, Thyroid glands (with parathyroid glands)
- Cesarean Section: uteri and the ovaries were removed and following data were recorded:
Weight of the unopened uterus, Number of corpora lutea, Number and distribution of implantation sites classified as live fetuses/dead implantations
(cf. "Ovaries and uterine content")

OTHER: CLINICAL PATHOLOGY prior to sacrifice on gestation day 20,
- Blood was taken from the retro-orbital venous plexus from not fasted animals
- Examinations:
- Hematology - WBC, RBC, HGB, HCT, MCV, MCH, MCHC, PLT, Differential blood count, Reticulocytes
- Clinical chemistry - enzymes: ALT, AST, ALP, GGT
- Clinical chemistry - blood chemistry parameter: INP, CA, UREA, CREA, GLUC, TBIL, TPROT, ALB, GLOB TRIG, CHOL

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number and distribution of implantations sites: Yes
- Number of live fetuses: Yes
- Number of dead implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
- Number of dead fetuses: Yes

Fetal examinations:

- External examinations: Yes
- Each fetus was weighed, sexed, and external tissues and all orifices were examined macroscopically
- Furthermore, the viability of the fetuses and the condition of placentae, umbilical cords, fetal membranes, and fluids were examined.
- Individual placental weights were recorded
- Fetuses were sacrificed: Approximately one half of the fetuses per dam were eviscerated, skinned and placed in ethanol,
the other half was placed in Harrison’s fluid for fixation
- Soft tissue examinations: Yes, fetuses fixed in Harrison’s fluid
- Skeletal examinations: Yes, fetuses fixed in ethanol
- Head examinations: No data

Statistics:

CLINICAL and FETAL EXAMINATIONS:
Food consumption, bw, bw change, corrected bw gain (net maternal bw change), carcass weight, weight of unopened uterus, number of corpora lutea, number of implantations, number of resorptions, number of live fetuses, proportions of preimplantation loss,
proportions of postimplantation, loss, proportions of resorptions, proportion of live fetuses in each litter, litter mean fetal body weight, litter mean placental weight; Female mortality, females pregnant at terminal sacrifice, number of litters with fetal findings; Proportions of fetuses with malformations, variations and/or unclassified observations in each litter.
PATHOLOGY:
Means and standard deviations of each test group were calculated. Weight parameters were evaluated.

Indices:

- Conception rate (in %) [number of pregnant animals/number of fertilized animals x 100]
- Preimplantation loss (in %) [(number of corpora lutea – number of implantations)/number of corpora lutea x 100]

Historical control data:

Gestational parameters of animals of this strain and age.

Details on maternal toxic effects:

Details on maternal toxic effects:
There were no substance-related or spontaneous mortalities in any of the groups. The oral administration of 250 and 750 mg/kg bw/d Morpholine hydrochloride caused a mild, regenerative anemia in the dams, along with increased liver weights. Additionally, transiently reduced mean food consumption and bw gain as well as affection of liver cells and liver cell metabolism was noted at the 750 mg/kg bw/d dose level. The oral administration of Morpholine hydrochloride to the dams at 75, 250 and 750 mg/kg bw/day had no influence on gestational parameters.

Dose descriptor:

NOAEL

Effect level:

75 mg/kg bw/day

Basis for effect level:

other: maternal toxicity

Dose descriptor:

NOAEL

Effect level:

750 mg/kg bw/day

Basis for effect level:

other: developmental toxicity

Details on embryotoxic / teratogenic effects:

Details on embryotoxic / teratogenic effects:
Fetal examinations revealed no influence of the test compound on sex distribution of the fetuses and fetal body weights. Morpholine hydrochloride shows no direct and specific effect on the respective morphological structures.

Abnormalities:

not specified

Developmental effects observed:

not specified

Fetal findings in this study were primarily limited to a slight increase in delayed ossification in the mid- and high-dose groups.These specific skeletal variations mirror common minor effects on fetal morphology which are considered to be transient in nature, being obviously secondary to maternal toxicity. Thus, these findings were regarded to be of no toxicological relevance and are not classified as adverse effects.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

535 mg/kg bw/day

Species:

rat

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

No studies are available for morpholinium toluene-4-sulphonate.

In a read-across assessment, morpholine was identified as the source chemical displaying the highest toxicity hazard when considering repeated exposure. Since no reliable conventional repeated dose oral toxicity study was available, an OECD 414 study was identified as key study and starting point for the read-across assessment.

Morpholine hydrochloride (97 % a.i.) was administered as an aqueous solution to 25 time-mated female Wistar rats (Crl:WI[Han]) by gavage at doses of 75, 250 or 750 mg/kg on gestation days 6 through 19 in a developmental toxicity study according to OECD 414 (BASF, 2009). The control group, consisting of 25 females, received vehicle (drinking water) in parallel. A standard dose volume of 10 mL/kg was used for each test group. At terminal sacrifice on GD 20, all females (25 per group) had implantation sites. The oral administration of 250 and 750 mg/kg caused a mild, regenerative anaemia in the dams, along with increased liver weights. Additionally, transiently reduced mean food consumption and bw gain as well as affection of liver cells and liver cell metabolism were noted at high dose. The oral administration of morpholine hydrochloride to the dams up to 750 mg/kg had no influence on gestational parameters. Conception rate, mean number of corpora lutea, total implantations, resorptions and live foetuses, foetal sex ratio, and the values calculated for pre- and postimplantation losses were all unaffected. The maternal NOAEL was set at 75 mg/kg based on statistically significant haematological changes in the dams at 250 and 750 mg/kg. Foetal examinations revealed no influence of morpholine hydrochloride on sex distribution of the foetuses and foetal body weights. Morpholine hydrochloride showed no direct and specific effect on the respective morphological structures. Foetal findings in this study were primarily limited to a slight increase in delayed ossification in the mid- and high-dose groups. These specific skeletal variations mirrored common minor effects on foetal morphology which are considered to be transient in nature, being obviously secondary to maternal toxicity. Thus, these findings were regarded to be of no toxicological relevance and were not classified as adverse events.Based on this study with morpholine hydrochloride, the NOAEL was set at 750 mg/kg, which - under consideration of mass proportions - corresponds to a NOAEL of 535 mg/kg for morpholine.No adverse foetal findings of toxicological relevance were evident at any dose.

In the developmental toxicity study, thirty (30) female rats received 0, 150, 1500 or 3000 mg test substance per kilogram body weight by oral gavage on days 6 to 15 of gestation. Clinical symptoms were noted daily through day 20. Body weight and food consumption were recorded every three days through day 20. All females were macroscopically examined on day 20. The uteri were removed, weighed and examined for number of corpora lutea, implant sites, and number and location of fetuses and resorptions. Fetuses were inspected on total number, sex, weight and external, visceral (one-half) and skeletal (one-half) defects. One death occurred at the 1500 mg/kg/day dose but it was considered a gavage injury. There were no abnormal clinical observations or necropsy findings. There were no effects on body weight or body weight gain. There was a significant increase in food consumption for the 3000 mg/kg/day dose during gestation interval (day) 12-16 but this was considered normal biological variation and not a direct effect of the test substance. All indices were comparable to the corresponding controls. The NOAEL was set at higher than 3000 mg/kg for maternal and developmental toxicity.

Justification for selection of Effect on developmental toxicity: via oral route:
The key study was selected based on the source chemical displaying the highest repeated dose toxicity hazard resulting from an OECD 414 study with Morpholine hydrochloride (BASF SE, 2009) which therefore was identified as key study and starting point for a read-across assessment.

Justification for classification or non-classification

Based on the data of the available studies morpholinium toluene-4 -sulphonate is considered to be no subject to classification for reproduction toxicity according to Directive 67/548/EEC (DSD) and according to Regulation (EC) No 1272/2008 (GHS/CLP).