Lithium nickel potassium oxide

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

December 2017 to April 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

yes

Test type:

traditional method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Lithium nickel potassium oxide

Cas Number:

210352-95-7

Molecular formula:

Li.K.Ni.O.H2O

IUPAC Name:

Lithium nickel potassium oxide

Test material form:

solid: particulate/powder

Details on test material:

Lithium nickel potassium oxide (KDLNO)
CAS Number:
210352-95-7
Appearance/Physical state:
Black powder
Storage: Room temperature in the dark

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST SYSTEM
Test species / strain: Rat / Wistar / Crl:WI(Han)
The female animals were nulliparous and non-pregnant.
Reasons for selection of the
test species:
Rats were selected since this rodent species is recommended in the respective test guidelines. Wistar rats were selected since there is extensive experience available in the laboratory
with this strain of rats.
The Wistar strain was also selected because extensive historical control data are available for this strain.
Age at day 0: Young adult animals (male animals approx. 8 weeks, female animals approx. 10 weeks)
Sex: Male / female
Supplier: Charles River Laboratories,
Research Models and Services, Germany GmbH,
Sandhofer Weg 7,
97633 Sulzfeld
Arrival in the testing facility: Acclimatization for at least 5 days before exposure.
Identification: Individual identification by cage cards and tail markings.
Body weight at day 0: Animals of comparable weight (± 20% of the mean weight,
actual weights)

Randomization: The animals were randomly selected from a pool of animals.

HOUSING AND DIET
Room temperature /
relative humidity:
The animals were housed in air-conditioned rooms. Central airconditioning
guaranteed a range of 20 – 24°C for temperature
and of 45 – 65 % for relative humidity. There were no deviations from these ranges, which influenced the results of the study.
There were 15 air changes per hour.
Day / night rhythm: 12 h / 12 h (6.00 a.m. – 6.00 p.m. / 6.00 p.m. – 6.00 a.m.)
The room was completely disinfected using a disinfector ("AUTEX", fully automatic, formalin ammonia- based terminal disinfector) before the start of the study. The floor and the walls
were cleaned once a week with water containing an appropriate disinfectant.

Type of cage: During the acclimatization period before exposure:
Typ 2000P: ca. 2065 cm2 (polysulfone cages) supplied by TECNIPLAST, Germany (caged in groups)
After exposure:
Typ III: (polycarbonate cages) (floor area about 800 cm2)
(for single housing)
Enrichment: Wooden gnawing blocks (Lignocel Block Large) J. Rettenmaier
& Söhne GmbH Co KG, Rosenberg, Germany and Play Tunnel,
large (Art. 14153); PLEXX b.v., Elst, Netherlands
Number of animals per cage: Single housing or up to 5 animals (caged in groups)
Feeding: Kliba laboratory diet, mouse/rat maintenance “GLP”, 12 mm
pellets, Provimi Kliba SA, Kaiseraugst, Basel Switzerland, ad
libitum
Drinking water: Tap water ad libitum
Bedding: Dust-free wooden bedding was used in this study (the present supplier is documented in the raw data).

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Mass median aerodynamic diameter (MMAD):

> 2.5 - < 3 µm

Details on inhalation exposure:

EXPOSURE
Nose-only inhalation system INA 10 (glass-steel construction, BASF SE, volume V ≈ 34 L): the
animals were restrained in glass tubes and their snouts projected into the inhalation system.
The homogenous distribution of test substance atmosphere/s in this inhalation system has
been verified with model aerosols.
Conditioned air:
The central air conditioning system provides cold air of about 15°C. This cold air passes
through an activated charcoal filter, is adjusted to room temperature of 20 to 24°C and passes
through a second particle filter (H13 (HEPA) Camfil Farr, Germany). The generated
conditioned air was used to generate inhalation atmospheres.
Compressed air:
Compressed air was produced by an oil-free compressor (HT 6, Josef Mehrer GmbH & Co KG,
Germany). For this purpose, air is filtered by an inlet air strainer and introduced into the
compressor. After passing through a second ultra-filter (SMF 5/3, 108 mm, Donalson), the
compressed air (15 bar) is stored in a storage of 1500 or 5000 L. The compressed air is
conducted to the laboratories via pipes, where the pressure is reduced to 6 bar. In the
laboratory, the compressed air can be taken as required.
Exhaust air:
The exhaust air was filtered and conducted into the exhaust air of the building.
The exposure system was located inside an exhaust cabin in an air-conditioned laboratory.
During each exposure, the following scheduled parameters were recorded four times at about
1-hour intervals:
Supply air flows: (compressed air plus conditioned air from a central air-conditioning system)
Test group 1: 0.8 m³/h (compressed air)
0.7 m³/h (conditioned air)
The flows were adjusted and continuously measured with a flowmeter (Yokogawa).
Supply air flows: (compressed air from a central air-conditioning system)
Test group 2 and 3: 1.0 m³/h
The flows were adjusted and continuously measured with a flowmeter (Yokogawa).
Exhaust air flows: Test group 1: 1.3 m³/h
Test group 2 and 3: 0.8 m³/h
The flows were adjusted and continuously measured with a flowmeter (Yokogawa).

The lower amounts of exhaust air, which were adjusted by means of a separate exhaust air
system, achieved positive pressures inside the exposure systems. This ensured that the
mixtures of test substance and air were not diluted with laboratory air in the breathing zones of
the animals.
Air changes of about 44 (test group 1) and 29 (test groups 2 and 3) times per hour can be
calculated by dividing the supply air flows by the volume of the inhalation systems.
The animals were exposed to the inhalation atmosphere for 4 hours plus equilibration time of
the inhalation systems (t99 about 6 min (test group 1) and 10 min (test groups 2 and 3)).
No surveillance of the oxygen content in the inhalation system was performed. The air change
was judged to be sufficient to prevent oxygen depletion by the breathing of the animals, and
the concentration of the test substance used could not have a substantial influence on oxygen
partial pressure.
Temperatures: The temperatures in the inhalation system were measured with a digital thermometer (Testo).
Relative humidities: The relative humidities in the inhalation system were measured with a dielectric probe (Testo).

Duration of exposure:

4 h

Remarks on duration:

The animals were exposed to the inhalation atmosphere for 4 hours plus equilibration time of
the inhalation systems (t99 about 6 min (test group 1) and 10 min (test groups 2 and 3)).

Concentrations:

The test was run with actual measured concentrations of 0.532 mg/L, 2.037 mg/L and
5.081 mg/L (analytical concentration).

No. of animals per sex per dose:

Five male and five female Wistar rats were used for each test group.

Details on study design:

TEST GROUPS
Five male and five female Wistar rats were used for each test group.

GENERATION OF THE INHALATION ATMOSPHERE
Test-substance preparation: The test substance was dosed unchanged.
Equipment: - Balance (Mettler)
- Flat-Tray Feeder (ZD 5 FB-C-1M-50, Three-Tec GmbH, Seon, Switzerland)
- Conducting tube made of stainless steel
- Pneumatic vibrator NCT 1 (NetterVibration, Mainz-Kastel, Germany)

Generation technique: For each concentration, appropriate amount of test substance
was dosed by the above mentioned flat-tray feeder. Applying compressed air, dust aerosols atmospheres were generated inside the inhalation system. The concentrations were adjusted by setting the pace of the double concave screw of the flat-tray feeder on a control panel.

EXPOSURE
Nose-only inhalation system INA 10 (glass-steel construction, BASF SE, volume V ≈ 34 L): the
animals were restrained in glass tubes and their snouts projected into the inhalation system.
The homogenous distribution of test substance atmosphere/s in this inhalation system has
been verified with model aerosols.
Conditioned air:
The central air conditioning system provides cold air of about 15°C. This cold air passes
through an activated charcoal filter, is adjusted to room temperature of 20 to 24°C and passes
through a second particle filter (H13 (HEPA) Camfil Farr, Germany). The generated
conditioned air was used to generate inhalation atmospheres.
Compressed air:
Compressed air was produced by an oil-free compressor (HT 6, Josef Mehrer GmbH & Co KG,
Germany). For this purpose, air is filtered by an inlet air strainer and introduced into the
compressor. After passing through a second ultra-filter (SMF 5/3, 108 mm, Donalson), the
compressed air (15 bar) is stored in a storage of 1500 or 5000 L. The compressed air is
conducted to the laboratories via pipes, where the pressure is reduced to 6 bar. In the
laboratory, the compressed air can be taken as required.
Exhaust air:
The exhaust air was filtered and conducted into the exhaust air of the building.
The exposure system was located inside an exhaust cabin in an air-conditioned laboratory.
During each exposure, the following scheduled parameters were recorded four times at about
1-hour intervals:
Supply air flows: (compressed air plus conditioned air from a central air-conditioning system)
Test group 1: 0.8 m³/h (compressed air)
0.7 m³/h (conditioned air)
The flows were adjusted and continuously measured with a flowmeter (Yokogawa).
Supply air flows: (compressed air from a central air-conditioning system)
Test group 2 and 3: 1.0 m³/h
The flows were adjusted and continuously measured with a flowmeter (Yokogawa).
Exhaust air flows: Test group 1: 1.3 m³/h
Test group 2 and 3: 0.8 m³/h
The flows were adjusted and continuously measured with a flowmeter (Yokogawa).

The lower amounts of exhaust air, which were adjusted by means of a separate exhaust air
system, achieved positive pressures inside the exposure systems. This ensured that the
mixtures of test substance and air were not diluted with laboratory air in the breathing zones of
the animals.
Air changes of about 44 (test group 1) and 29 (test groups 2 and 3) times per hour can be
calculated by dividing the supply air flows by the volume of the inhalation systems.
The animals were exposed to the inhalation atmosphere for 4 hours plus equilibration time of
the inhalation systems (t99 about 6 min (test group 1) and 10 min (test groups 2 and 3)).
No surveillance of the oxygen content in the inhalation system was performed. The air change
was judged to be sufficient to prevent oxygen depletion by the breathing of the animals, and
the concentration of the test substance used could not have a substantial influence on oxygen
partial pressure.
Temperatures: The temperatures in the inhalation system were measured with a digital thermometer (Testo).
Relative humidities: The relative humidities in the inhalation system were measured with a dielectric probe (Testo).

Statistics:

STATISTICAL EVALUATION
LC50 values, 4-hour exposure
LC50 (female rats)1): 2.048 mg/L
While mortality of female animals increased in the concentration-related manner, no males
died at the highest tested concentration of about 5 mg/L, but two of five males died at the mid
concentration of about 2 mg/L. None of the males died at the lowest concentration of about
0.5 mg/L. This patter is considered as biological variability, demonstrated a flat dose-response
relationship in the males. The overall data of males were consistent to those of the females.
Due to the missing dose-response relation in the lethality rate of male Wistar rats, meaningful
statistical evaluation is not possible. LC50 of male animals is considered to be > 2.037 mg/L.
_____________
1) Probit analysis for female animals.
No statistical evaluation for males and both sexes combined.

Results and discussion

Effect levels

Effect levels 1

Key result

Sex:

female

Dose descriptor:

LC50

Effect level:

2.048 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Effect levels 2

Key result

Sex:

male

Dose descriptor:

LC50

Effect level:

> 2.037 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

Test group 1 (0.532 mg/L):
One of five female animal were sacrificed in a moribund state on study day 6. No lethality was
observed in males.
Test group 2 (2.037 mg/L):
Two of the five male animals and two of the five females died or were sacrificed in a moribund
state after exposure on study days 4 or on study day 7 during the post-exposure observation
period.
Test group 3 (5.081 mg/L):
Four of the five female animals and none of the five males died or were sacrificed in a moribund
state on study days 5 or 8 during the post-exposure observation period.

Clinical signs:

bodyweight loss

Body weight:

Test group 1 (0.532 mg/L)
The mean body weights of the male animals decreased on the first post-exposure observation
days but increased thereafter. The mean body weights of the surviving female animals
decreased on the first post-exposure observation week but increased thereafter.
Test group 2 (2.037 mg/L)
The mean body weights of the surviving male animals decreased on the first post-exposure
observation days but increased thereafter. The mean body weights of the surviving female
animals decreased on the first post-exposure observation week but increased thereafter.
Test group 3 (5.081 mg/L)
The mean body weights of the male animals decreased on the first post-exposure observation
days but increased thereafter. The mean body weights of the surviving female animals
decreased on the first post-exposure observation week but increased thereafter.

Other findings:

Clinical signs of toxicity in animals exposed to 0.532 mg/L comprised accelerated and
intermittent respiration, labored respiration, respiration sounds, no feces, poor general state,
piloerection and substance-contaminated fur. Findings were observed from hour 3 of exposure
until the end of the post-exposure observation period of 14 days. The mean body weights of
the male animals decreased on the first post-exposure observation days but increased
thereafter. The mean body weights of the surviving female animals decreased on the first post exposure observation week but increased thereafter. During necropsy of the dead female
animal, dark-red discoloration and partly surface sunken was seen in all lobes of the lung. At
termination of the study, in two female animals few dark-red foci and partly sunken surface of
the lung was noted. The remaining male and female animals did not show any gross
pathological abnormality.

Clinical signs of toxicity in animals exposed to 2.037mg/L included accelerated and intermittent
respiration, abdominal respiration, respiration sounds, semiclosed eyelid, red discharge and
red encrusted nose, poor general state, piloerection, substance like encrusted nose and
substance-contaminated and discolored (substance like) fur. Findings were observed from
hour 3 of exposure until the end of the post-exposure observation period of 14 days. The mean
body weights of the surviving male animals decreased on the first post-exposure observation
days but increased thereafter. The mean body weights of the surviving female animals
decreased on the first post-exposure observation week but increased thereafter. During
necropsy of the dead animals (two males and two females), only one female showed dark-red
discoloration of the lung. The remaining dead animals did not show any gross pathological
abnormality. At the termination of the post exposure observation period gross
pathology revealed partly swelling in lungs of all males, or dark-red foci and sunken surface
of the lung in all females.

Clinical signs of toxicity in animals exposed to 5.081 mg/L comprised accelerated and
intermittent respiration, respiration labored, abdominal respiration, red discharge of the nose,
poor general state, hypothermia, hunched posture, piloerection, diarrhea, black discolored feces, substance-contaminated and discolored (substance like) fur. Findings were observed
from hour 2 of exposure until the end of the post-exposure observation period of 14 days. The
mean body weights of the male animals decreased on the first post-exposure observation days
but increased thereafter. The mean body weights of the surviving female animals decreased
on the first post-exposure observation week but increased thereafter. During necropsy of the
four dead female animals, only one of them showed macroscopic changes characterized by
dark-red discoloration and partly sunken surface in all lobes of the lung, and additional black
foci in the stomach. The other dead females did not show any gross pathological abnormality.
Remaining male and female animals sacrificed at the end of the post-exposure observation
period showed no gross pathological abnormalities.

Histopathological examination of the lungs was conducted in animals Nos. 172 and 178
(sacrificed on 14 days after exposure to 2.037 mg/L). Histopathology revealed an interstitial
inflammation accompanied by alveolar fibrosis, interstitial and alveolar edema and additional
histiocytosis (with black particles) in the lungs of both animals.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Executive summary:

SUMMARY

To determine the acute inhalation toxicity (single 4-hour exposure, nose only) of KDLNO as a dust aerosol, a study was performed in male and female Wistar rats according to OECDGuideline method 403, as well as EC.

The test was run with actual measured concentrations of 0.532 mg/L, 2.037 mg/L and 5.081 mg/L (analytical concentration).

Cascade impactor measurements resulted in particle size distributions with mass median aerodynamic diameters (MMADs) between 2.5 and 3.0 μm, which are well within the respirable range.

One of the five females and no males were sacrificed in a moribund state at 0.532 mg/L. Two of five males and two of five females died or were sacrificed in a moribund state at 2.037 mg/L. At 5.081 mg/L no males and four of five female animals died or were sacrificed in a moribund state. Mortality was observed from study day 4 up to 8 days after the end of the exposure.

Clinical signs of toxicity in animals exposed to 0.532 mg/L comprised accelerated and intermittent respiration, labored respiration, respiration sounds, no feces, poor general state, piloerection and substance-contaminated fur. Findings were observed from hour 3 of exposure until the end of the post-exposure observation period of 14 days. The mean body weights of the male animals decreased on the first post-exposure observation days but increased thereafter. The mean body weights of the surviving female animals decreased on the first postexposure
observation week but increased thereafter. During necropsy of the dead female
animal, dark-red discoloration and partly surface sunken was seen in all lobes of the lung. At termination of the study, in two female animals few dark-red foci and partly sunken surface of the lung was noted. The remaining male and female animals did not show any gross pathological abnormality.

Clinical signs of toxicity in animals exposed to 2.037mg/L included accelerated and intermittent respiration, abdominal respiration, respiration sounds, semiclosed eyelid, red discharge and red encrusted nose, poor general state, piloerection, substance like encrusted nose and substance-contaminated and discolored (substance like) fur. Findings were observed from hour 3 of exposure until the end of the post-exposure observation period of 14 days. The mean body weights of the surviving male animals decreased on the first post-exposure observation days but increased thereafter. The mean body weights of the surviving female animals
decreased on the first post-exposure observation week but increased thereafter. During necropsy of the dead animals (two males and two females), only one female showed dark-red discoloration of the lung. The remaining dead animals did not show any gross pathological abnormality. At the termination of the post exposure observation period gross pathology revealed partly swelling in lungs of all males, or dark-red foci and sunken surface of the lung in all females.

Clinical signs of toxicity in animals exposed to 5.081 mg/L comprised accelerated and intermittent respiration, respiration labored, abdominal respiration, red discharge of the nose, poor general state, hypothermia, hunched posture, piloerection, diarrhea, black discolored feces, substance-contaminated and discolored (substance like) fur. Findings were observed from hour 2 of exposure until the end of the post-exposure observation period of 14 days. The mean body weights of the male animals decreased on the first post-exposure observation days but increased thereafter. The mean body weights of the surviving female animals decreased on the first post-exposure observation week but increased thereafter. During necropsy of the four dead female animals, only one of them showed macroscopic changes characterized by dark-red discoloration and partly sunken surface in all lobes of the lung, and additional black foci in the stomach. The other dead females did not show any gross pathological abnormality. Remaining male and female animals sacrificed at the end of the post-exposure observation period showed no gross pathological abnormalities.

 

Histopathological examination of the lungs was conducted in animals Nos. 172 and 178 (sacrificed on 14 days after exposure to 2.037 mg/L). Histopathology revealed an interstitial inflammation accompanied by alveolar fibrosis, interstitial and alveolar edema and additional histiocytosis (with black particles) in the lungs of both animals. 

 

Under the current study conditions, the LC50 value for female Wistar rats was 2.048 mg/L (calculated based on analytical concentration) after a 4-hour inhalation exposure to the dust aerosol of KDLNO. The LC50 value for male Wistar rats is considered to be > 2.037 mg/L (based on analytical concentration) after a 4-hour inhalation exposure to the dust aerosol of KDLNO although.