Chloramide

Repeated dose toxicity: oral

Administrative data

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

publication

Title:

Comparative subchronic toxicity of chlorine and monochloramine in the B6C3F1 mouse.

Author:

Daniel F.B, Ringhand H.P., Robinson M., Stober J.A., Olson G.R., and Page N.P.

Year:

1991

Bibliographic source:

Journal (American Water Works Association) Vol. 83, No. 11, Health Effects (NOVEMBER 1991), pp. 68-75

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Deviations:

yes

Remarks:

No satellite group. The wet weight of Epididymides and uterus were not taken.

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Chloramide

EC Number:

234-217-9

EC Name:

Chloramide

Cas Number:

10599-90-3

Molecular formula:

ClH2N

IUPAC Name:

chloranamine

Test material form:

other: in aqueous solution

Details on test material:

- Substance type: formulation
- Physical state: liquid

Test animals

Species:

mouse

Strain:

B6C3F1

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Portage, Mich.
- Age at study initiation: no data
- Weight at study initiation: 23.9 to 24.6 g for males/ 19.1 to 19.5 g for females
- Fasting period before study: no
- Housing: 5 animals per cage
- Diet : ad libitum (Purina certified Chow 5002, Ralston-Purina Co., St Louis, Mo)
- Water: ad libitum (tap water)
- Acclimation period: 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-22
- Humidity (%): 40- 60
- Air changes (per hr): no data
- Photoperiod : 12 hrs dark / 12 hrs light

IN-LIFE DATES: no data

Administration / exposure

Route of administration:

oral: drinking water

Vehicle:

other: carbonate buffer

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
Monochloramine stock solutions (about 3,500 ppm) were prepared by adding 50 ml of the stock chlorine solution to 500 ml of distilled water. This solution was added slowly to 400 ml of distilled water containing 5 ml of concentrated ammonium hydroxide and 2 ml of 6N hydrochloric acid. The actual dosing solutions were prepared by diluting the stock monochloramine solution with pH 9.4 carbonate buffer. Because stability studies indicated that monochloramine solutions undergo at 7 to 10 percent decomposition over a period of three days at room temperature, the actual drinking water solutions were prepared at a concentration 10 percent desired, i.e., 15, 22, 55, 110, and 220 mg/l.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analysis of the monochloramine concentration by the DPD method showed that the 220 mg/l solutions averaged 190 +/- 7 mg/l when the bottles were removed from the animal cages after three days, thus confirming the previously determined decomposition rates. Similar levels of loss were observed for the lower concentrations of monochloramine.

Duration of treatment / exposure:

90 days

Frequency of treatment:

daily

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 12.5, 25, 50, 100 and 200 mg/l (0, 2.5, 5, 10, 20 and 40 mg/kg/d)
Basis:
nominal in water

No. of animals per sex per dose:

10

Control animals:

yes

Details on study design:

- Dose selection rationale: The planned dosage levels had been selected based on previous studies conducted by the authors' laboratory and at the National Toxicology Program laboratories and were projected from the concentrations of chemical added to the drinking water and normal drinking water consumption.

Positive control:

None

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily


DETAILED CLINICAL OBSERVATIONS: Yes / No / No data
- Time schedule:

BODY WEIGHT: Yes
- Time schedule for examinations: Body weughts were recorded at the initiation of the study, weekly during exposure, and at the time of necropsy.


FOOD EFFICIENCY:
- 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: Yes / No / No data

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes
- Time schedule for examinations: Water consumption was determined three times a week.

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

HAEMATOLOGY: Yes
- Time schedule for collection of blood: Blood samples were collected via cardiac puncture prior to sacrifice.
- Anaesthetic used for blood collection: Yes (60 mg/kg of pentobarbital)
- Animals fasted: No data
- How many animals: 10 males and 10 females per dose level


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: Blood samples were collected via cardiac puncture prior to sacrifice.
- Animals fasted: No data
- How many animals: 10 males and 10 females per dose level


URINALYSIS: No


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

OTHER:

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

Other examinations:

None

Statistics:

The standard statistical procedure used was a one-factor analysis of variance (ANOVA) for normally distributed measures. Males and females were considered separately in all statistical analyses, and the parameters analyzed were body weight, organ weights, organ-to-body weight ratios, water and food consumption, hematology, and clinical chemistry measurements. The differences between the control and treatment groupswere analyzed pairwise using an ANOVA contrast prodecure at an adjusted significance level to control the false positive rate (overall alpha = 0.05). Because of the high variability of some of the clinical chemistry measures, a nonparametric analysis of variance, i.e., the Kruskal-Wallis test, was also employed to determine differences among the dosage groups and to compare pairwise each dosage group to the control group. analyses of the gross and microscopic pahtology diagnoses are limited to descriptive statistics.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

The body weight gains were significantly depressed at the three highest concentrations in males and the two highest concentrations in females.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

food consumption was decreased in both males and females, and the change was significant for the females at the two highest concentrations.

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY
No animals died during the study. Toxic effects were not evident during routine cage-side examination.

BODY WEIGHT AND WEIGHT GAIN
The body weight gains were significantly depressed at the three highest concentrations in males and the two highest concentrations in females.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
Food consumption was decreased in both males and females, and the change was significant for the females at the two highest concentrations.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study)
Significant differences were alsoobserved in the water consumption of males at the two highest concentrations and of females at all monochloramine concentrations.

HAEMATOLOGY
A variety of changes in hematology was observed, although no effect was determined to be consistently treatment or dosage-related. The most consistent effects in both sexes were increased WBCs. In males an increase in lymphocytes at 100 and 200 mg/l and in females a decrease in neutrophils at 100 mg/l and a significant decrease in MCV at all dosage levels were the most remarkable changes.

CLINICAL CHEMISTRY
Several minor changes in clinical chemistries were noted, with no consistent treatment-related pattern. ALK-P was decreased in males at all concentration (significant at 25, 50, and 100 mg/l), whereas AST was significantly increased in females at all dosage levels (significant at 50 and 200 mg/l). LDH was significantly decreased at 25 mg/l in males but was significantly increased at 200 mg/l.

ORGAN WEIGHTS
Compared with the controls, numerous significant reductions in absolute organ weights were evident in the male and female animals drinking 200 mg monochloramine/l, with lesser effects seen for the lower concentrations. For example, for both males and females, liver and heart weights were decreased at the top two concentrations, and spleen weights (relative and absolute) were decreased at the two high dosages for females. At the highest dosage, the kidney and lung weights were decreased for both males and females, and absolute testes and spleen weight, some organs - brain, kidney, lung, and testes (males) and brain and kidney (females) - were significantly increased at the higher dosages compared with the control values.

GROSS PATHOLOGY
No compound-reated gross or microscopic lesions were observed.

HISTOPATHOLOGY: NON-NEOPLASTIC
No target tissues were identified in monochloramine-treated animals, and all lesions observed were interpreted as either agonal changes or incidental background findings.

Effect levels

Dose descriptor:

NOAEL

Effect level:

8.5 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

other: Decreased organ weights

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Under the conditions of this test, no treatment-related pathology was observed.

Executive summary:

Separate groups of male and female B6C3F1 mice were administered monochloramine in drinking water for 90 consecutive days. Monochloramine was supplied at 12.5, 25, 50, 100, and 200 mg/L. Criteria evaluated included mortality, clinical signs, body weight, food consumption, hematology, clinical chemistry, organ weights, gross pathology, and histopathology. Overall, the correlation of the biochemical, hematological, and organ weight data, in the absence of histopathology and observable clinical signs of toxicity, suggests that the monochloramine induced effects via an indirect mechanism, e.g., nutritional deficiencies, rather than a direct toxicological effect on specific organs or tissues.