[carbonato(2-)]tetrahydroxytrinickel

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

other: Defined LC50

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

[carbonato(2-)]tetrahydroxytrinickel

EC Number:

235-715-9

EC Name:

[carbonato(2-)]tetrahydroxytrinickel

Cas Number:

12607-70-4

Molecular formula:

Ni3(OH)4CO3

IUPAC Name:

trinickel monocarbonate tetrahydroxide

Details on test material:

- Name of test material (as cited in study report): Nickel hydroxycarbonate
- Physical state: green powder
- Analytical purity: 100%
- Stability under test conditions: was expected to be stable for the duration of testing
- Storage condition of test material: room temperature under nitrogen
- Other: soluble in water: 34.5 mg/L (pH 6); 7.1 mg/L (pH 8)

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Ace Animals, Inc., Boyertown, PA on July 28, September 1 and 29, and October 27, 2009
- Age at study initiation: 8 - 10 weeks
- Weight at study initiation: males: 275-356 grams, and females: 204-242 grams
- Fasting period before study: not reported
- Housing: singly housed in suspended stainless steel caging with mesh floors which conform to the size recommendations in the most recent Guidefor the Care and Use ofLaboratory Animals (Natl. Res. Council, 1996). Litter paper was placed beneath the cage and was changed at least three tnnes per week.
- Diet (e.g. ad libitum): Purina Rodent Chow #5012
- Water (e.g. ad libitum): Tap water was supplied ad libitum by an automatic water dispensing system except during exposure
- Acclimation period: 10, 14, or 15 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-24%
- Humidity (%): 46-81%; the humidity was above the targeted upper limit for 15 days during the study. A portable dehumidifier was used to decrease the humidity levels during this time.
- Air changes (per hr): 284
- Photoperiod (hrs dark / hrs light): 12-hour light/dark cycle


IN-LIFE DATES (Day 3): August 12, September 16, and November 9, 2009

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Nose Only Inhalation Chamber, ADG Developments, LTD
- Exposure chamber volume: 6.7 L
- Method of holding animals in test chamber: polycarbonate holding tubes
- Source and rate of air: air compressor (JUN-AIR, Model #6-15)
- Method of conditioning air: test substance packed into dust container and compressed to 250 lbs.in2 using a lab press. Compressed air was supplied to dust generator at 30 psi.
- System of generating particulates/aerosols: Wright Dust Generator driven by variable speed motor (Dayton, Model #4Z538A or a D.C. speed control with 0-100 potentiometer.
- Method of particle size determination: An eight-stage Andersen cascade impactor was used to assess the particle size distribution of the test atmosphere. Samples were withdrawn from the breathing zone of the animals at two intervals during each exposure. The fIlter paper collection stages were weighed before and after sampling to determine the mass collected upon each stage. The aerodynamic mass median diameter and geometric standard deviation were determined graphically using two-cycle logarithmic probit axes.
- Treatment of exhaust air: no data
- Temperature, humidity, pressure in air chamber: temperature and relative humidity values were recorded every 15 minutes for the fIrst hour ofexposure and every 30 minutes thereafter.


TEST ATMOSPHERE
- Brief description of analytical method used: Gravimetric samples were withdrawn at five or six intervals from the breathing zone ofthe animals during each exposure. Samples were collected using 25 mm glass fIber fIlters (GF/B Whatman) in a filter holder attached by 1/4-inch tygon tubing to a vacuum pump (Reliance Electric, Model #G557X). Filter papers were weighed before and after collection to determine the mass collected. This value was
divided by the total volume of air smnpled to determine the chamber concentration. Sample airflows were measured using a Mass Flowmeter (Omega, Model #FMA-5610).
- Samples taken from breathing zone: yes


VEHICLE
not applicable


TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: 1.9-3.2 um
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): 1.9, 2.0, 2.5, and 3.2 um for doses 0.053, 0.25, 1.06, and 2.09 mg/L, respectively

Analytical verification of test atmosphere concentrations:

yes

Remarks:

gravimetric sampling

Duration of exposure:

4 h

Concentrations:

0.053, 0.261, 1.06, and 2.09 mg nickel carbonate/L

No. of animals per sex per dose:

5 males for all 4 dose groups; 5 females only for the highest dose group

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: prior to exposure, and 7 and 14 days post exposure
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs (included gross evaluation of skin and fur, eyes and mucous membranes, respiratory, circulatory, autonomic and central nervous systems, somatomotor activity and behavior pattern, including tremors, convulsions, salivation, diarrhea, and coma), body weight, and gross pathology (focus on thoracic and abdominal caveties).

Statistics:

Probit Analysis; Finney, D.J., Probit Analysis, 3rd ed., Cambridge University Press, Cambridge, Great Britain, 1971, pp.1-333 was used for data analysis of LC50 and confidence limit calculations.

Results and discussion

Preliminary study:

Not applicable

Effect levels

Effect levels 1

Sex:

female

Dose descriptor:

LC50

Effect level:

> 2.09 mg/L air (analytical)

Exp. duration:

4 h

Remarks on result:

other: One animal died at this the only dose to which females were exposed.

Effect levels 2

Sex:

male

Dose descriptor:

LC50

Effect level:

0.244 mg/L air (nominal)

95% CL:

> 0.001 - < 49.7

Exp. duration:

4 h

Remarks on result:

other: Calculated by Probit Method.

Mortality:

0.053 mg/L (males only): none
0.261 mg/L (males only): all 5 animals died by Day 5.
1.06 mg/L (males only): 3 animals died between Days 3-5. Remaining 2 animals survived to the end of the study.
2.09 mg/L (females and males): 4 males and 1 female died between Days 4-5. Remaining animals survived to the study's conclusion.

Clinical signs:

other: 0.053 mg/L (males only): 3 rats exhibited reduced fecal volume and 1 also appeared hypoactive by Day 3, but all affected animals recovered from these symptoms by Day 7. 0.261 mg/L (males only): immediately following exposure all animals appeared active an

Body weight:

0.053 mg/L (males only): 1 rat failed to gain body weight through Day 7, all animals gained weight over the entire observation period
0.261 mg/L (males only): all animals had lost weight by time of death.
1.06 mg/L (males only): both survivors lost weight through Day 7, but gained weight over the entire 14-day observation period; all three decedents had lost weight by time of death.
2.09 mg/L (females and males): 4 of the 5 surviving rats lost body weight through Day 7, but all 5 survivors gained weight over the entire 14-day observation period; all 5 decedents had lost weight by the time of death.

Gross pathology:

0.053 mg/L (males only): no gross abnormalities were noted for any of the animals.
0.261 mg/L (males only): discoloration of the lungs and intestines.
1.06 mg/L (males only): discoloration of the lungs and intestines in the 3 decedents; no gross abnormalities in 2 survivors.
2.09 mg/L (females and males): discoloration of the lungs and intestines in the decedents; no gross abnormalities in survivors.

Other findings:

NOAEC (male): 0.053 mg nickel hydroxycarbonate/L.

Any other information on results incl. tables

Incidence of Mortality

Exposure Levels (mg/L)	Males	Females	Total
0.053	0/5	-*	0/5
0.261	5/5	-*	5/5
1.06	3/5	-*	3/5
2.09	4/5	1/5	5/10

*based on the results of the 2.09 mg/L exposure level, only five males were tested at the 0.053, 0.261 and 1.06 mg/L

levels.

Applicant's summary and conclusion

Interpretation of results:

Category 2 based on GHS criteria

Conclusions:

Under the conditions of this study, the acute inhalation LC50 of Nickel hydroxycarbonate is greater than 2.09 milligrams of the test substance per liter of air in female rats. The defined LC50 for male rats calculated by Probit Method is 0.2437 mg/L with 95% Confidence Limits of 49.6996 mg/L (upper) and 0.0012 mg/L (lower). The data does not permit calculation of the LC50 for females by Probit Analysis. NOAEC (male): 0.053 mg nickel hydroxycarbonate/L.

Executive summary:

Eurofins Product Safety Laboratories (EPSL, 2010) conducted an acute inhalation toxicity test (nose-only exposure) with eight to ten week old male and female Sprague-Dawley albino rats to determine the LC50 for nickel hydroxycarbonate. After establishing the desired generation procedures during pre-test trials, a total of twenty-five healthy rats (20 male and 5 female) were selected for the test. Exposure concentrations were 0.05, 0.25, 1.0 and 2.0 mg nickel hydroxycarbonate/L air; exposure duration was 4 hours. Chamber concentration and particle size distributions of the test substance were determined periodically during the exposure period. The actual analytical concentrations reported were 0.053, 0.261, 1.06, and 2.09 mg/L, and the 9 corresponding particle size measurements (MMAD) were 1.9, 2.0, 2.5, and 3.2 μm, respectively. Five males and five females were exposed to 2.0 mg nickel hydroxycarbonate/L air; four males and one female died at this dose. Because the females were minimally affected by the highest dose, only five males were selected for the 0.05, 0.25 and 1.0 mg/L exposures. The animals were observed for mortality, signs of gross toxicity, and behavioral changes at least once daily for 14 days following exposure or until death occurred. Body weights were recorded prior to exposure and again on Days 7 and 14 or after death. Necropsies were performed on all animals.

All five male rats in the lowest exposure group (0.053 mg/L) gained weight and survived to necropsy, displaying no gross pathologies. Other than one case of hyperactivity and three cases of reduced fecal volume early in the study, all rats in this dose group recovered from these symptoms and appeared to be active and healthy by Day 7 of the study. All five animals exposed to 0.261 mg nickel hydroxycarbonate/L died between Days 3 and 5 of the study. Within two days following exposure all rats exhibited abnormal respiration, tremors and/or reduced fecal volumes, and necropsy showed that all five animals had discolored lungs and intestines. Three of the animals in the 1.06 mg/L exposure group died between Days 3 and 5 of the study, with the remaining two animals surviving to necropsy. All five animals exhibited irregular respiration, hypoactivity, hunched posture and/or reduced fecal volume immediately after exposure, though the surviving animals recovered by Day 7 and appeared active and healthy for the remainder of

the observation period. The rats that did not survive until necropsy lost body weight by the time of death and gross necropsy demonstrated discolored lungs and intestines; no gross abnormalities were reported in the two surviving animals at necropsy. In the high-dose group, all 10 rats exhibited clinical signs including abnormal respiration, facial staining, hypoactivity, hunched posture and/or reduced fecal volume immediately following exposure. All surviving animals recovered from the above symptoms by Day 13. Five (four males and one female) of the ten animals in the highest-dose group lost weight and died by Day 4 of the study. The five survivors

lost weight through by Day 7, but had an overall net weight gain by necropsy. The animals that did not survive showed discolored lungs and intestines at time of death, while necropsy of the survivors did not demonstrate any abnormal gross pathologies.

Under the conditions of this study, the study authors calculated the acute inhalation LC50 of nickel hydroxycarbonate in female rats to be greater than the highest dose tested, 2.09 mg/L. The defined LC50 for male rats calculated by Probit Method was 0.2437 mg/L with 95% confidence limits of 49.6996 mg/L (upper) and 0.0012 mg/L (lower). STUDY RATED BY AN INDEPENDENT REVIEWER.