Methyl methanesulphonate

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

short-term repeated dose toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from peer reviewed publication

Data source

Reference

Reference Type:

publication

Title:

Inhalation Carcinogenesis of Various Alkylating Agents

Author:

Arthur R. Sellakumar, Carroll A. Snyder and Roy E. Albert

Year:

1987

Bibliographic source:

J. Natl Cancer Inst, VOL. 79, NO.2, AUGUST 1987, page no. 285-289

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Refer below principle

Principles of method if other than guideline:

Repeated dose inhalation toxicity study was performed to determine the toxic nature of Methylmethane sulfonate in rat upon repeated exposure

GLP compliance:

not specified

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Methyl methanesulphonate

EC Number:

200-625-0

EC Name:

Methyl methanesulphonate

Cas Number:

66-27-3

Molecular formula:

C2H6O3S

IUPAC Name:

methyl methanesulfonate

Details on test material:

- Name of test material: Methylmethane sulfonate (MMS)
- Molecular formula: C2H6O3S
- Molecular weight: 110.1324 g/mole
- Substance type: Organic
- Physical state: Liquid
- Impurities (identity and concentrations): < 5 %

Specific details on test material used for the study:

- Name of test material : Methylmethane sulfonate (MMS)
- Molecular formula: C2H6O3S
- Molecular weight: 110.1324 g/mol
- Substance type: Organic
- Physical state: Liquid
- Purity: > 95%
- Impurities (identity and concentrations): < 5 %

Test animals

Species:

rat

Strain:

Sprague-Dawley

Details on species / strain selection:

No data

Sex:

male

Details on test animals or test system and environmental conditions:

Details on test animal
TEST ANIMALS
- Source: Charles River Breeding Laboratories, Wilmington, MA
- Age at study initiation: 11 to 12-week-old
- Weight at study initiation: 325 ± 16.8 g,
- Fasting period before study: No data available
- Housing: No data available
- Diet (e.g. ad libitum): Purina Lab Chow, ad libitum, except during exposure periods.
- Water (e.g. ad libitum): Water, ad libitum, except during exposure periods.
- Acclimation period: 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): No data available
- Humidity (%):No data available
- Air changes (per hr): No data available
- Photoperiod (hrs dark / hrs light): No data available

IN-LIFE DATES: From: To: No data available

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Remarks on MMAD:

MMAD / GSD: No data available

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Dynamic exposure Chambers
- Method of holding animals in test chamber: No data available
- Source and rate of air: Airstream
- Method of conditioning air: Airstream over the liquids in a generating flask and then feeding the effluent vapor into the chamber air supply.
- System of generating particulates/aerosols: Test atmospheres of the chemicals were generated by passing an airstream over the liquids in a generating flask and then feeding the effluent vapor into the chamber air supply.
- Temperature, humidity, pressure in air chamber: No data available
- Air flow rate: 1.0 m3 or 1.3 m3
- Air change rate: No data available
- Method of particle size determination: Wilks Miran infrared gas analyzer were use to determine the particle size.
- Treatment of exhaust air: No data available

TEST ATMOSPHERE
- Brief description of analytical method used: Chamber concentrations of the chemicals were analyzed at half-hour intervals during the daily exposures by means of a Wilks Miran infrared gas analyzer with the use of appropriate wavelength.
- Samples taken from breathing zone: No data available

VEHICLE (if applicable)
- Justification for use and choice of vehicle: Air
- Composition of vehicle: No data available
- Type and concentration of dispersant aid (if powder): No data available
- Concentration of test material in vehicle: 0 or 50 ppm (0 or 5 mg/L)
- Lot/batch no. of vehicle (if required): No data available
- Purity of vehicle: No data available

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

No data

Duration of treatment / exposure:

30 days

Frequency of treatment:

6 hr/day X 5 days/wk

Doses / concentrations

Remarks:

0 or 5 mg/L

No. of animals per sex per dose:

Total : 178
0 ppm (0 mg/L): 98
50 ppm (5 mg/L): 80

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: 50 ppm (5 mg/L) dose was used for MMS because of the cost of compound.
- Rationale for animal assignment (if not random): Animal was assigned to test group randomly.
- Rationale for selecting satellite groups: No data available
- Post-exposure recovery period in satellite groups: No data available
- Section schedule rationale (if not random): No data available

Positive control:

No data

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Daily
- Cage side observations checked in table [No.?] were included: Mortality

DETAILED CLINICAL OBSERVATIONS: No data available
- Time schedule: No data available

BODY WEIGHT: Yes
- Time schedule for examinations: Monthly

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): No data available
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No data available
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No data available

FOOD EFFICIENCY: No data available
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No data available

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data available
- Time schedule for examinations: No data available

OPHTHALMOSCOPIC EXAMINATION: No data available
- Time schedule for examinations: No data available
- Dose groups that were examined: No data available

HAEMATOLOGY: No data available
- Time schedule for collection of blood: No data available
- Anaesthetic used for blood collection: No data available
- Animals fasted: No data available
- How many animals: No data available
- Parameters checked in table [No.?] were examined: No data available

CLINICAL CHEMISTRY: No data available
- Time schedule for collection of blood: No data available
- Animals fasted: No data available
- How many animals: No data available
- Parameters checked in table [No.?] were examined: No data available

URINALYSIS: No data available
- Time schedule for collection of urine: No data available
- Metabolism cages used for collection of urine: No data available
- Animals fasted: No data available
- Parameters checked in table [No.?] were examined: No data available

NEUROBEHAVIOURAL EXAMINATION: No data available
- Time schedule for examinations: No data available
- Dose groups that were examined: No data available
- Battery of functions tested: sensory activity / grip strength / motor activity / other: No data available

OTHER: No data available

Sacrifice and pathology:

Sacrifice and pathology
GROSS PATHOLOGY: Yes

Organs examined :
Trachea, larynx, liver, kidneys, testes, and any other organs

HISTOPATHOLOGY: Yes
A complete necropsy was performed on each animal. The nasal passages were flushed with 10% neutral buffered Formalin; then the entire head and other organs were fixed in the same fixative. The head was then decalcified; and stepwise cross-sections were taken in the dorsoventral plane perpendicular to the long axis of the skull, beginning just posterior to the nostrils and extending caudal as far as the orbit. Histologic sections were taken from each lobe of the lung and from the trachea, larynx, liver, kidneys, testes, and any other organs exhibiting gross pathology. Paraffin sections, 4-5 /µm thick, were prepared in the usual fashion and stained with hematoxylin-eosin and with special stains, if necessary.

Organs examined :
Nasal passages, entire head, lung, Trachea, larynx, liver, kidneys, testes, and any other organs were examined

Other examinations:

No data available

Statistics:

No data available

Results and discussion

Results of examinations

Clinical signs:

not specified

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

effects observed, treatment-related

Other effects:

not specified

Details on results:

Clinical signs and mortality
Mortality: Cumulative mortality was observed in treated rat as compare to control.

Clinical signs: No data available

Body weight and weight gain: No data available

Food consumption and compound intake: No data available

Food efficiency: No data available

Water consumption and compound intake: No data available

Opthalmoscopic examination: No data available

Haematology: No data available

Clinical chemistry: No data available

Urinanalysis: No data available

Neurobehaviour: No data available

Organ weights: No data available
Gross pathology: Metastatic lesions in the lungs were noted in 2 animals dying of nasal squamous cell carcinomas, Squamous metaplasia, Polyp or papillomas lesions were observed in treated rat as compare to control.

Histopathology:
High incidences of nasal tumor, potent carcinogenic effect on the nasal epithelium, adenomatous polyps in larynx, adenomatous polyps in trachea, malignant lymphoma, adenoma in adrenal, adenocarcinoma in adrenal, papilloma in skin, adenomas in thyroid, islet cell adenoma in pancreas, fibro adenomas in mammary gland, adenocarcinoma in salivary gland, adenoma in salivary gland, lipomas in subcutaneous, fibromas in subcutaneous and adenoma in parathyroid.

47 (59%) developed tumors of the nasal mucosa with the first carcinoma being observed in animal dying at 256 days.

Effect levels

Dose descriptor:

LOAEC

Effect level:

5 mg/L air (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: Effect on Mortality, gross pathology and histopathology.

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

Table: Median life-span and time of tumor appearance following exposure to alkylating agents

Treatment	No. of animals	Median life days	Animals with tumors, No (%)	Time of tumor appearance, days
				Median	Range
5 mg/L X 30 exp	80	495	47 (59)	513	256-775

 

Table: Specific types of tumors and other lesions of the nasal mucosa in rats exposed to various alkylating agents

	Treatment	MMS, 5 mg/L X 30 exp
	No. of animals examined	80
No. of tumors and other lesions of nasal mucosa	Tumors bearing animals, No (%)	47 (59)
	Rhinitis	49
	Squamous metaplasia	5
	Polyps or papillomas	11
	Squamous cell carcinoma	33
	Adenocarcinoma	2
	Mixec carcinoma	2
	Osteogenicsarcome	-

Applicant's summary and conclusion

Conclusions:

The low-observed-adverse-effect concentration (LOAEC) was considered to be 5 mg/L air (50ppm) when Sprague-Dawley male rat were exposed to Methylmethane sulfonate (MMS) upon repeated exposure for 30 days.

Executive summary:

Repeated dose inhalation toxicity study was performed to determine the toxic nature of Methylmethane sulfonate (MMS) in rat upon repeated exposure. 11 -12 week old Male Sprague Dawley rat were exposed to MMS at a dose level of 0 or 5 mg/L for 30 days. All animals were observed daily, weighed monthly, and allowed to die spontaneously or sacrificed when moribund. A complete necropsy was performed on each animal. The nasal passages were flushed with 10% neutral buffered Formalin and the entire head and other organs were fixed in the same fixative. The head was then decalcified; and stepwise cross-sections were taken in the dorsoventral plane perpendicular to the long axis of the skull, beginning just posterior to the nostrils and extending caudal as far as the orbit. Histologic sections were taken feom each lobe of the lung and from the trachea, larynx, liver, kidneys, testes, and any other organs exhibiting gross pathology. Paraffin sections, 4-5 µm thick, were prepared in the usual fashion and stained with hematoxylin-eosin and with special stains for histologic examination. Cumulative mortality was noted in the test animals. Gross pathological examinations revealed the presence of metastatic lesions in the lungs in 2 animals dying of nasal squamous cell carcinomas, squamous metaplasia and polyp or papillomas lesions were observed in treated rat as compare to control. In addition, High incidences of nasal tumor, potent carcinogenic effect on the nasal epithelium, adenomatous polyps in larynx, adenomatous polyps in trachea, malignant lymphoma, adenoma in adrenal, adenocarcinoma in adrenal, papilloma in skin, adenomas in thyroid, islet cell adenoma in pancreas, fibro adenomas in mammary gland, adenocarcinoma in salivary gland, adenoma in salivary gland, lipomas in subcutaneous, fibromas in subcutaneous and adenoma in parathyroid were observed. 47 (59%) developed tumors of the nasal mucosa with the first carcinoma being observed in animal dying at 256 days. On the basis of observations made, the low-observed-adverse-effect concentration (LOAEC)  was considered to be 5 mg/L air (50ppm) when Sprague-Dawley male rat were exposed to Methylmethane sulfonate (MMS) upon repeated exposure for 30 days.