Registration Dossier
Registration Dossier
Data platform availability banner - registered substances factsheets
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.
The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.
Diss Factsheets
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 930-930-0 | CAS number: -
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Endpoint summary
Administrative data
Description of key information
Repeated dose toxicity - oral:
Hydrogen peroxide: Key study: OECD Guideline 408. GLP study: Reduced food and water consumption were seen at ≥ 300 ppm. Body weight was reduced in mice receiving 3000 ppm during most of treatment period in male animals. Further signs of treatment indicated the duodenum as target organ with local mucosal hyperplasia at ≥ 1000 ppm. Mucosal hyperplasia in the duodenum was not found in any dose group after recovery. The no observed adverse effect level (NOAEL) was 100 ppm (26 mg/kg bw/day in males and 37 mg/kg bw/day in females).
Calcium lactate: Key study: Similar to OECD Guideline 453. It was concluded that calcium lactate had neither toxic nor carcinogenic activity in F344 rats when it was given continuously in the drinking-water for 2 yr at a dose up to 5% drinking water. Therefore, the NOAEL for both chronic toxicity and carcinogenicity was determined to be 5% drinking water, i.e. 2150 and 2280 mg/kg bw/day to male and female rats respectively, corresponding to 279.5 and 296.4 mgCa/kg bw/day (860 and 570 mgCa/rat).
Repeated dose toxicity - inhalation:
Hydrogen peroxide: Key study: OECD Guideline 412. GLP study. Local effects appeared in the nose with necrosis and inflammation at ≥10 ppm followed by respiratory irritation and reduced body weight gain in higher exposure concentrations. The no observed adverse effect level (NOAEL) was 2.9 mg/m³ (2.03 ppm).
Key value for chemical safety assessment
Repeated dose toxicity: via oral route - systemic effects
Link to relevant study records
- Endpoint:
- sub-chronic toxicity: oral
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- other: see 'Remark'
- Remarks:
- The study was performed in essential accordance with the OECD Guideline for Testing of Chemicals No. 408 with restrictions. No FOB and motor activity measurements were performed as they were not requested by the guideline at the time the study was performed.
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)
- Deviations:
- yes
- Remarks:
- None relevant for the integrity and validity of the study: no FOB and motor activity measurements were performed as they were not requested by the guideline at the time the study was performed (there were no indications for neurotoxic effects); blood clot
- GLP compliance:
- yes
- Limit test:
- no
- Species:
- mouse
- Strain:
- other: C57BL/6NCrlBR
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Charles River Laboratories
- Age at study initiation: 5 weeks
- Weight at study initiation:
- Fasting period before study: no data
- Housing: individually in suspended, stainless steel cages with wire bottom
- Diet (e.g. ad libitum): Purina Rodent Chow 5002 (meal) ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 7 days
ENVIRONMENTAL CONDITIONS
- Temperature: 65 to 71 °F
- Humidity (%): 41 to 78
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12 hours light/12 hours darkness - Route of administration:
- oral: drinking water
- Vehicle:
- water
- Details on oral exposure:
- The treated (and control) water for this study was prepared twice weekly and administered to the animals on the day of preparation. The drinking water solutions were made by adding preweighed amounts of 35 % hydrogen peroxide to distilled water. The solutions were mixed in carboys for at least 15 minutes prior to dispending the animals. Following administration, unused portions of treated water were stored refrigerated. All equipment for water solution preparation and administration was passivated with nitric acid before use.
- Analytical verification of doses or concentrations:
- yes
- Details on analytical verification of doses or concentrations:
- Samples of the 100-ppm hydrogen peroxide stock solution and the 3000-ppm hydrogen peroxide stock solution used to dose mice at the 100 ppm and 3000 ppm hydrogen peroxide levels were taken together with a blank sample and analysed for concentration and homogeneity. A colourimetric analytical method designated Test Method APG No. 332 was applied which uses a ferrus thiocyanate reagent. The colour absorbance was measured with a Perkin Elmer Lambda 18 Spectrophotometer. Subsequently, on each of four date one distilled water blank, one control sample of 100 ppm and 3000 ppm hydrogen peroxide and five samples of 100 ppm and 3000 ppm dose solutions were analysed by the same method. Additionally, the 35 % hydrogen peroxide solution was analysed by an iodometric titration at 30 day intervals up to 120 days to test the stability of the solution under the storage conditions (4 °C, vented closed container).
- Duration of treatment / exposure:
- Approximately 90 days
- Frequency of treatment:
- Mice received drinking water ad libitum
- Remarks:
- Doses / Concentrations:
0, 100, 300, 1000 or 3000 ppm
Basis:
nominal in water - No. of animals per sex per dose:
- Number of animals per group: 15/sex per treatment group; 10/sex were killed after ceasing the exposure period, whereas 5/sex were submitted to a six week recovery period.
- Control animals:
- yes
- Details on study design:
- C57BL/6NCRlBR mice were chosen due to their particular sensitivity to hydrogen peroxide because of a deficient detoxification pathway. The strain can therefore be regarded as a very sensitive animal model for this particular substance.
- Observations and examinations performed and frequency:
- Clinical signs: daily
Mortality: twice daily
Body weight: weekly
Food consumption: weekly
Water consumption: twice weekly
Blood analysis, haematology, clinical chemistry analyses: blood samples were taken immediately before the scheduled necropsy
Ophthalmic examinations: the eyes of all animals were checked for lesions before the study and one week before the study termination and only animals showing no lesions were used in the study - Sacrifice and pathology:
- Animals that died before the study termination underwent a complete necropsy upon discovery of death. Animals sacrificed at their scheduled termination (days 91-93 of treatment period, days 133-134 of recovery period) were anaesthetised, bled for haematology and clinical chemistry determinations, sacrificed via exsanguination then necropsied. Animals were not fasted prior to sacrifice. The weights were determined of brain, liver, kidneys, spleen, testes, adrenals and heart. Samples from various tissues were saved in 10 % buffered formalin. All slides of organs and tissues in the control and high dose groups as well as tissues from mice that died out of schedule were investigated by an experienced pathologist and histological examinations were performed on all gross lesions, the tongue, esophagus, stomach, duodenum, ileum, jejunum, caecum, colon and rectum of all animals from all groups.
- Statistics:
- Body weights, food consumption, water consumption, absolute organ weights, organ:brain weight ratios, haematology and clinical chemistry data were analysed using the Ebar-Squared trend test. The test compared data from the high-dose group to control and computed a p-value to indicate whether the measured parameter was significantly different (p < 0.05 for statistically significant difference). Subsequent analyses compared data from the next highest dosage group to control, in the direction of the overall trend, and generated another p-value. These analyses continued in a stepwise manner for successively lower groups until the p-value was greater 0.05. When the trend test returned a value greater than 0.05, no subsequent comparisons of the lower dosage groups were performed.
- Clinical signs:
- no effects observed
- Mortality:
- no mortality observed
- Body weight and weight changes:
- effects observed, treatment-related
- Food consumption and compound intake (if feeding study):
- effects observed, treatment-related
- Food efficiency:
- not specified
- Water consumption and compound intake (if drinking water study):
- effects observed, treatment-related
- Ophthalmological findings:
- no effects observed
- Haematological findings:
- no effects observed
- Clinical biochemistry findings:
- effects observed, treatment-related
- Urinalysis findings:
- not examined
- Behaviour (functional findings):
- not specified
- Organ weight findings including organ / body weight ratios:
- no effects observed
- Gross pathological findings:
- effects observed, treatment-related
- Histopathological findings: non-neoplastic:
- effects observed, treatment-related
- Histopathological findings: neoplastic:
- no effects observed
- Details on results:
- No treatment-related deaths occurred and no treatment-related clinical signs were noted at any time of the study. Male and females exhibited significant reductions in body weight at 3000 ppm. Food and water consumption were significantly reduced at 3000 ppm and notably reduced at 1000 and 300 ppm. Males receiving 3000 ppm displayed significant reductions in total protein and globulin levels in the blood, possibly caused by mucosal hyperplasia occurring in the duodenum of these animals. Necropsy revealed no treatment-related gross lesions. Tissue slides indicated an increase in the cross sectional diameter and wall thickness of the duodenum. Subsequent microscopic evaluations revealed mild mucosal hyperplasia in eight of nine males receiving 3000 ppm and in seven of ten males receiving 1000 ppm. Minimal mucosal hyperplasia was noted in one of ten males receiving 300 ppm. Minimal to mild mucosal hyperplasia was also seen in ten of ten females receiving 3000 ppm and in eight of ten females receiving 1000 ppm. No other areas of the gastrointestinal tract were affected. No evidence of cellular atypia or architectural disruptions nor any other indications of neoplastic changes were observed; therefore, the treatment-related mucosal hyperplasia noted was not considered as a neoplastic lesion.
- Key result
- Dose descriptor:
- NOEL
- Effect level:
- 100 ppm
- Sex:
- male/female
- Basis for effect level:
- other: 26 and 37 mg/kg bw/day for males and females, respectively; dose-related reductions in food and water consumption were seen at the next higher doses level of 300 ppm; additionally, duodenal mucosal hyperplasia was observed at 300 ppm
- Key result
- Critical effects observed:
- no
- Conclusions:
- No treatment-related effects were observed at 100 ppm dose level and the LOEL, based on decreased food and water consumption and the observation of duodenal mucosal hyperplasia, was 300 ppm.
- Executive summary:
A 90-day oral, subchronic toxicity study with a 35 % aqueous solution of hydrogen peroxide dissolved in drinking water to produce concentrations ranging from 100 to 3000 ppm was performed with C57BL/6NCrlBR mice under GLP conditions and in essential accordance with OECD Guideline No. 408. C57BL/6NCRlBR mice were chosen due to their particular sensitivity to hydrogen peroxide because of a deficient detoxification pathway. The strain can therefore be regarded as a very sensitive animal model for this particular substance. Groups of 15 males and 15 females received different doses of hydrogen peroxide dissolved in their drinking water. After the 90 -day exposure duration, 10 animals/sex of each dose group were sacrificed, while the remaining five animals/sex were submitted to a six week recovery period. No treatment-related mortality or clinical signs were noted throughout the study. No other treatment-related effects were observed at the 100 ppm dose level. At 300 ppm, the consumption of food and water was reduced. Tissue slides indicated an increase in the cross sectional diameter and wall thickness of the duodenum. Subsequent microscopic evaluations revealed mild mucosal hyperplasia in eight of nine males and ten of ten females receiving 3000 ppm and in seven of ten males and eight of ten females receiving 1000 ppm. Minimal mucosal hyperplasia was noted in one of ten males but in none of the females receiving 300 ppm. No other areas of the gastrointestinal tract were affected. Microscopically, no evidence of cellular atypia or architectural disruptions nor any other indications of neoplastic changes were observed; therefore, the treatment-related mucosal hyperplasia noted in the study was not considered as neoplastic lesion. Based on dose-related reductions in food and water consumption and the observation of duodenal mucosal hyperplasia the lowest observed effect level in the study was 300 ppm and the no observed effect level (NOEL) was 100 ppm (26 and 37 mg/kg/day for males and females, respectively). Clinical pathologic effects (decreased total protein and globulin blood levels) were limited to the 3000 ppm level. All effects noted during the treatment period were reversible; animals sacrificed following the recovery period were considered biologically normal.
- Endpoint:
- chronic toxicity: oral
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- comparable to guideline study with acceptable restrictions
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 453 (Combined Chronic Toxicity / Carcinogenicity Studies)
- Deviations:
- yes
- Remarks:
- experimental design is poorly described.
- Principles of method if other than guideline:
- The long-term toxicity/carcinogenicity of calcium lactate, a food additive, was examined in F344 rats. Calcium lactate was given ad lib. in the drinking water at levels of 0, 2.5 or 5 % to groups of 50 male and 50 female rats for two years.
- GLP compliance:
- not specified
- Limit test:
- no
- Species:
- rat
- Strain:
- Fischer 344
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Charles River Japan Inc. (Kanagawa, Japan).
- Females (if applicable) nulliparous and non-pregnant: [yes/no]
- Age at study initiation: 6 wk old
- Weight at study initiation:
- Fasting period before study:
- Housing: Three (or four) males or five females to a plastic cage
- Diet (e.g. ad libitum): Ad libitum, basal diet (CRF-1; Oriental Yeast Inc., Tokyo, Japan)
- Water (e.g. ad libitum): Ad libitum, tap-water
- Acclimation period:
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 24 ± 1
- Humidity (%): 55 ± 5 - Route of administration:
- oral: drinking water
- Details on route of administration:
- The calcium lactate solutions were replaced with freshly prepared solutions three times a week, on which occasions the amount of solutions consumed was measured in order to calculate the intake of calcium lactate. Administration of the compound ended after 104 wk, and the rats were then given distilled water for a recovery period of 9wk.
- Vehicle:
- water
- Details on oral exposure:
- - PREPARATION OF DOSING SOLUTIONS:
Calcium lactate was dissolved in distilled water at levels of 0 (control), 2.5 or 5%. - Duration of treatment / exposure:
- Treatment: 104 weeks.
Recovery period: 9 weeks. - Frequency of treatment:
- Daily.
- Dose / conc.:
- 5 other: % drinking water
- Dose / conc.:
- 2.5 other: % drinking water
- No. of animals per sex per dose:
- 50
- Control animals:
- yes, concurrent vehicle
- Details on study design:
- - Dose selection rationale: These doses were selected after a 13-wk subchronic toxicity study done prior to the present study (Matsushima et al., 1989).
- Observations and examinations performed and frequency:
- CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Daily
DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Daily
BODY WEIGHT: Yes
- Time schedule for examinations: Once a week for the first 13 wk of the study, and every 4 wk thereafter.
WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes
- Time schedule for examinations: The calcium lactate solutions were replaced with freshly prepared solutions three times a week, on which occasions the amount of solutions consumed was measured in order to calculate the intake of calcium lactate.
OPHTHALMOSCOPIC EXAMINATION: Not specified
HAEMATOLOGY: Yes
CLINICAL CHEMISTRY: Yes
URINALYSIS: Not specified
NEUROBEHAVIOURAL EXAMINATION: Not specified - Sacrifice and pathology:
- GROSS PATHOLOGY: Yes
The animals were then examined macro- and microscopically for the presence of non-neoplastic and neoplastic lesions.
HISTOPATHOLOGY: Yes
All organs and/or tissues were routinely fixed in 10% buffered formalin, sectioned and stained with haematoxylin and eosin. - Statistics:
- Statistical analyses were performed using Fisher's exact probability test and/or the chi-square test, and also the age-adjusted statistical test recommended by Peto et al. (1980).
- Clinical signs:
- not specified
- Mortality:
- mortality observed, non-treatment-related
- Description (incidence):
- In females, the mortality rate in the 5% group was slightly higher than those in the other two groups. This difference, however, was not significant.
- Body weight and weight changes:
- effects observed, treatment-related
- Description (incidence and severity):
- Throughout the administration period, there was a dose-dependent inhibitory effect of calcium lactate on the growth of rats of both sexes. Compared with the controls, a 13% decrease in body-weight gain was observed in male and female rats of the high-dose group.
- Water consumption and compound intake (if drinking water study):
- no effects observed
- Description (incidence and severity):
- Daily water consumption was almost constant in all groups of both sexes.
- Haematological findings:
- no effects observed
- Description (incidence and severity):
- No specific dose-related changes were observed in any of the haematological parameters.
- Clinical biochemistry findings:
- no effects observed
- Description (incidence and severity):
- No specific dose-related changes were observed in any of the biochemical parameters.
- Organ weight findings including organ / body weight ratios:
- effects observed, non-treatment-related
- Description (incidence and severity):
- A significant dose-dependent increase was observed in the relative brain weights of both male and female rats although no histological change was detected. Females in the 5% group exhibited slightly but significantly higher kidney weights compared with controls.
- Gross pathological findings:
- effects observed, non-treatment-related
- Description (incidence and severity):
- A number of nonneoplastic lesions (e.g. myocardial fibrosis, bile-duct proliferation, hepatic microgranulomas and chronic nephropathy) were observed in all groups, with no difference in their incidences and/or degrees.
- Histopathological findings: non-neoplastic:
- effects observed, non-treatment-related
- Description (incidence and severity):
- There was no difference in the severity of chronic nephropathy between different groups. No toxic lesions such as severe cortico-medullary nephrocalcinosis were observed in the kidney of females in the 5% group despite a slight increase in calcium deposition in the papilla compared with controls. There was no difference in histological findings of the parathyroid gland between different groups of both sexes; also no metastatic calcification was detected in the various organs/tissues.
- Histopathological findings: neoplastic:
- effects observed, non-treatment-related
- Description (incidence and severity):
- The incidences of total tumours were 100% in all the male groups. In females, they were 80-86%, and there was no significant difference in the incidences between different groups. Tumours were found in many organs and/or tissues in all groups including the controls. In males from all groups, tumours of the testis were the most frequent, followed by those of the adrenal gland, thyroid gland, pituitary gland, haematopoietic organs, mammary gland, lung and pancreas. In females, the commonest tumours were those of the uterus, pituitary gland, haematopoietic organs, mammary gland, thyroid gland, adrenal gland and pancreas. Tumours were also detected in other organs/tissues from rats of all groups, but at lower incidences. Histologically, all the tumours observed in this experiment were similar to those known to occur spontaneously in F344 rats. None of the experimental groups showed a significant increase in the incidence of any specific tumours compared with the corresponding control value (chisquare and/or Fisher's test), and also no positive trend was noted in the occurrence of any tumour. Male rats in the 5% group, however, showed a slightly higher incidence of pheochromocytomas compared with the present controls and also with our historical controls (12-28%). The incidence of adrenal medullary hyperplasias in the high-dose group (24%) was also higher than that in the lowdose
and control groups (12% and 10%, respectively). A positive trend was observed in the occurrence of the two types of lesions (combined hyperplasias and pheochromocytomas). - Key result
- Dose descriptor:
- NOAEL
- Effect level:
- 2 150 mg/kg bw/day (actual dose received)
- Based on:
- test mat.
- Sex:
- male
- Basis for effect level:
- other: No test item related adverse effects at the highest dose
- Remarks on result:
- other: corresponding to 279.5 mgCa/kg bw/day (860 mgCa/rat)
- Key result
- Dose descriptor:
- NOAEL
- Effect level:
- 2 280 mg/kg bw/day (actual dose received)
- Based on:
- test mat.
- Sex:
- female
- Basis for effect level:
- other: No test item related adverse effect observed at the highest dose tested
- Remarks on result:
- other: corresponding to 296.4 mgCa/kg bw/day (570 mgCa/rat)
- Key result
- Critical effects observed:
- no
- Conclusions:
- It was concluded that calcium lactate had neither toxic nor carcinogenic activity in F344 rats when it was given continuously in the drinking-water for 2 yr at a dose up to 5% drinking water. Therefore, the NOAEL for both chronic toxicity and carcinogenicity was determined to be 5% drinking water, i.e. 2150 and 2280 mg/kg bw/day to male and female rats respectively, corresponding to 279.5 and 296.4 mgCa/kg bw/day (860 and 570 mgCa/rat).
- Executive summary:
The aim of the present study was to examine the toxicity/carcinogenicity of calcium lactate ingested over a long period. 50 F344 rats per sex and dose were exposed to calcium lactate by drinking water. Based in a previous 13 weeks subchronic toxicity test, calcium lactate was dissolved in distilled water at levels of 0 (control), 2.5 or 5%. The calcium lactate solutions were replaced with freshly prepared solutions three times a week, on which occasions the amount of solutions consumed was measured in order to calculate the intake of calcium lactate. Administration of the compound ended after 104 weeks, and the rats were then given distilled water for a recovery period of 9 weeks. At week 113, all surviving animals were killed and autopsied. Haematological and biochemical examinations were also carried out in these rats. They were observed daily and clinical signs and deaths were recorded. Body weights were measured once a week for the first 13 weeks of the study, and every 4 week thereafter. An autopsy was immediately performed on rats that died (or were killed when moribund) during the study and those killed at the end of the study. The animals were then examined macro- and microscopically for the presence of non-neoplastic and neoplastic lesions. All organs and/or tissues were routinely fixed in 10% buffered formalin, sectioned and stained with haematoxylin and eosin. In females, the mortality rate in the 5% group was slightly higher than those in the other two groups. This difference, however, was not significant. Throughout the administration period, there was a dose-dependent inhibitory effect of calcium lactate on the growth of rats of both sexes. Compared with the controls, a 13% decrease in body-weight gain was observed in male and female rats of the high-dose group. No specific dose-related changes were observed in any of the haematological and biochemical parameters. The anatomical sites and histological characteristics of the tumours were similar to those of spontaneous tumours, which occur commonly in the strain of rats studied. There is an established link between serum calcium levels and adrenal medullary function. Rats are very susceptible to the development of hyperplastic and neoplastic changes in the adrenal medulla in response to high levels of serum calcium. However, the serum calcium levels recorded in treated rats of both sexes were not different from the corresponding control levels. There was also no difference in histological findings of the thyroid and parathyroid glands and kidney and bone between different groups. In addition, the incidence of pheochromocytomas observed in the present male controls was also higher than that in our historical controls. Furthermore, no significant increase or positive trend in the incidences of hyperplasias/pheochromocytomas was detected in females from all groups. Thus, we consider that the increase in hyperplasias/pheochromocytomas of male rats in the high-dose group was probably due to experimental variability and not related to treatment with calcium lactate. The results from this study also show that many kinds of non-neoplastic lesions were detected in male and female rats from all groups. No clear toxic lesions specifically caused by long-term administration of calcium lactate, except for the slight calcium deposition in the renal papilla, were detected in any organ. The type of lesion observed in the kidney of female rats in the 5% group was histologically different from the so-called nephrocalcinosis, which is characterized by an intraluminal deposition of calcium observed mainly in the cortico-medullary region. The pathogenesis of this lesion is unclear and might depend on the increase in the urinary calcium level. The observed increase in relative brain weights of males and females in the high-dose group may result from the decrease in body-weight gains and not to the toxic effect of calcium lactate. It was concluded that calcium lactate had neither toxic nor carcinogenic activity in F344 rats when it was given continuously in the drinking-water for 2 yr. Based on these results, the NOAEL for both chronic toxicity and carcinogenicity was determined to be 5% drinking water, i.e. 2150 and 2280 mg/kg bw/day to male and female rats respectively, corresponding to 279.5 and 296.4 mgCa/kg bw/day (860 and 570 mgCa/rat).
Referenceopen allclose all
Table 1: Results of analysis of stock solution (35 % hydrogen peroxide), dose solutions (100, 300, 1000 and 3000 ppm), and mean hydrogen peroxide consumption.
Stability of refrigerated 35 % test material |
Range of % of target concentration in dose solutions |
Hydrogen peroxide consumption (mg/kg/day) based on water consumption and nominal conc. |
|||||
Time point of sampling |
Total % hydrogen peroxide |
% change from initial analysis |
Group |
Target concentration (ppm) |
Initial range, % of target |
Males |
Females |
Initial analysis |
35.1 |
NA |
1 |
0 |
NA |
NA |
NA |
30-day analysis |
35.0 |
-0.3 |
2 |
100 |
94.8-102 |
26 ± 6.0 |
37 ± 10.0 |
60-day analysis |
34.7 |
-1.1 |
3 |
300 |
98.0-105 |
76 ± 17.1 |
103 ± 25.5 |
90-day analysis |
34.7 |
-1.1 |
4 |
1000 |
102-105 |
239 ± 56.4 |
328 ± 81.4 |
120-day analysis |
34.7 |
-1.1 |
5 |
3000 |
101-104 |
547 ± 95.3 |
785 ± 194.3 |
NA: not applicable
Table 2: Development of body weights, food and water consumption throughout the study
sex |
males |
females |
||||||||
group |
0 |
1 |
2 |
3 |
4 |
0 |
1 |
2 |
3 |
4 |
ppm |
0 |
100 |
300 |
1000 |
3000 |
0 |
100 |
300 |
1000 |
3000 |
Body weight [g/animal] |
||||||||||
Day 0 |
19.7 |
19.7 |
19.6 |
19.6 |
19.7 |
16.6 |
16.6 |
16.7 |
16.7 |
16.7 |
Day 21 |
23.2 |
22.5 |
22.3 |
22.7 |
21.6 |
19.6 |
20.0 |
19.9 |
19.6 |
19.1 |
Day 42 |
24.9 |
24.5 |
24.1 |
24.5 |
23.6¯ |
22.1 |
22.5 |
22.3 |
21.7 |
21.7 |
Day 63 |
26.3 |
25.5 |
25.5 |
25.7 |
24.9¯ |
23.2 |
21.7 |
22.7 |
22.5 |
22.7 |
Day 91 |
28.1 |
27.1 |
27.3 |
27.2 |
26.7¯ |
25.1 |
24.9 |
25.2 |
24.8 |
24.1 |
Weight gain |
9.2 |
8.4 |
8.7 |
9.2 |
7.3¯ |
8.5 |
10.3 |
10.6 |
10.4 |
8.9 |
Mean food consumption [g/animal/week] |
||||||||||
Day 7 |
31 |
33 |
31 |
32 |
24¯ |
27 |
31 |
26 |
27 |
27 |
Day 35 |
39 |
41 |
35 |
38 |
36 |
56 |
45 |
40¯ |
36¯ |
39¯ |
Day 63 |
40 |
40 |
38 |
40 |
34¯ |
68 |
69 |
68 |
62 |
56¯ |
Day 91 |
43 |
41 |
43 |
41 |
36¯ |
47 |
48 |
46 |
35¯ |
39¯ |
Mean water consumption [g/animal/week] |
||||||||||
Day 7 |
39 |
41 |
38 |
33 |
25¯ |
38 |
42 |
44 |
33 |
26¯ |
Day 35 |
52 |
52 |
43 |
47 |
33¯ |
90 |
75 |
56¯ |
61¯ |
52¯ |
Day 63 |
39 |
35 |
35 |
32 |
26¯ |
46 |
42 |
42 |
42 |
33¯ |
Day 91 |
40 |
37 |
41 |
36 |
35¯ |
47 |
50 |
48 |
48 |
43 |
-- Indicates a decrease in comparison with controls
Table 3: Results of clinical chemistry (blood samples)
parameter changed |
control |
100 ppm |
300 ppm |
1000 ppm |
3000 ppm |
|
Males |
||||||
Total protein |
g/dL |
4.7 |
4.6 |
4.8 |
4.5 |
4.2¯ |
Globulin |
g/dL |
2.0 |
2.1 |
1.9 |
1.9 |
1.5¯ |
Females |
||||||
Total protein |
g/dL |
4.9 |
4.8 |
4.6 |
4.7 |
4.5 |
Globulin |
g/dL |
2.3 |
2.2 |
2.1 |
2.1 |
2.0 |
-- Indicates a decrease in comparison with controls
Table 4: Incidence of histopathological findings
Parameter |
Control |
100 ppm |
300 ppm |
1000 ppm |
3000 ppm |
|||||
m |
f |
m |
f |
m |
f |
m |
f |
m |
f |
|
number of animals examined |
9 |
10 |
10 |
10 |
10 |
10 |
10 |
10 |
9 |
10 |
duodenum - mucosal hyperplasia |
0 |
0 |
0 |
0 |
1 |
0 |
7 |
8 |
8 |
10 |
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed
Repeated dose toxicity: inhalation - systemic effects
Link to relevant study records
- Endpoint:
- short-term repeated dose toxicity: inhalation
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- other: The study was carried out in accordance with the respective OECD Guidelines and under GLP conditions. No deviations were reported that were likely to negatively influence the outcomes of the study.
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 412 (Subacute Inhalation Toxicity: 28-Day Study)
- Deviations:
- no
- GLP compliance:
- yes
- Limit test:
- no
- Species:
- rat
- Strain:
- other: Alpk:ApfSD (Wistar derived)
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Rodent Breeding Unit, Alderley Park, Macclesfield, UK
- Age at study initiation: 6 to 7 weeks
- Weight at study initiation: for groups 1-4, 242.5 +/- 9.6 g (males), 190.2 +/- 12.3 g (females); four groups five and six, 300.3 +/- 9.1 g (males), 233.8 +/- 11.0 g (females)
- Fasting period before study:
- Housing: five rats, sexes separately, in stainless steel cages
- Diet (e.g. ad libitum): CT1 supplied by Special Diet Services Ltd, Witham, UK ad libitum
- Water (e.g. ad libitum): mains water ad libitum
- Acclimation period: 5 days
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 30-70
- Air changes (per hr): at least 15
- Photoperiod (hrs dark / hrs light): 12 hours light/12 hours darkness - Route of administration:
- inhalation
- Type of inhalation exposure:
- whole body
- Vehicle:
- other: unchanged (no vehicle)
- Remarks on MMAD:
- MMAD / GSD: not applicable
- Details on inhalation exposure:
- Test atmospheres were generated using a glass concentric-jet atomiser to generate fine aerosol directly into a 3-necked quick-fit round bottomed flask, heated by placing it in a waterbath at 80 °C. The test substance was pumped to the atomiser using a peristaltic pump, typically operating at a pump speed giving a flow rate of test material of approximately 1 mL/min. Clean, dry air was passed through the atomiser at nominal flow rates of 2, 10 or 15 L/minute for groups 2, 3 and 4 respectively, and (together with heated generation air at 25 L/minute) carried the atmosphere to the lng term exposure chamber. Diluting air was added directly to the exposure chambers at a flow rate of 500-600 L/min. Air flows were monitored continuously using variable area flowmeters.
- Analytical verification of doses or concentrations:
- yes
- Details on analytical verification of doses or concentrations:
- Test atmospheres were sampled by passing the atmosphere, at a fixed flow rate for a known time period, through a known volume of de-ionised water in a midget impinger. The resulting solutions were analysed by flow injection analysis using a LC Module 1 (Waters) separations module at a flow rate of 5 L/minute, a dilute Cobalt-bicarbonate reagent mobile phase, and a 486 series UV detector (Waters) at 260 nm. The limit of detection of the method was assessed to be approximately 0.1 mg/mL corresponding to an atmosphere concentration of 0.1 ppm.
- Duration of treatment / exposure:
- 28 days
- Frequency of treatment:
- 6 hours daily, 5 days per week
- Remarks:
- Doses / Concentrations:
2.03, 10.3, 23.3, 58.1/27.3 ppm (2.88, 14.6, 33, 82.4/38.7 mg/m3)
Basis:
analytical conc. - No. of animals per sex per dose:
- five males, five females
- Control animals:
- yes
- Details on study design:
- Another group (group 4 of the main test) of animals was exposed to 60 ppm at day 1, 4, 5 and 6. Thereafter, the exposure level was reduced to 30 ppm at day 11 and 12. The treatment was terminated on day 13 and animals were sacrificed due to toxicity. The group treated with a target concentration of 25 ppm was introduced later in the test after termination of the test group 4 (60/30 ppm).
- Observations and examinations performed and frequency:
- Clinical observations: prior to the start of the study, frequently during exposure and at the end of the 6 hour exposure duration, daily before exposure
Body weight: before study initiation, weekly during exposure study
Food consumption: continuously throughout the study
Clinical pathology (haematology, blood clinical chemistry): at termination of study - Sacrifice and pathology:
- Animals were killed by an overdose of halothane Ph. Eur. vapour followed by exsanguination. Weights of adrenal glands, kidneys, liver, lungs and testes were measured. All animals were subjected to full examination post mortem including external and careful internal examination of all organs and structures. Slides were prepared from various organs and tissues. All submitted tissues from control and high exposure animals together with the lungs, liver, kidney, trachea, nasal passages and abnormal tissues from the low and mid exposure groups were routinely processed, embedded in paraffin wax, sectioned at 5 micrometre and stained with haematoxylin and eosin. Examination by light microscopy was performed for these tissues.
- Statistics:
- Body weights were considered by analysis of covariance on initial body weight, separately for males and females. Haematology and blood clinical chemistry were considered by analysis of variance. Male and female data were analysed together. Organ weights were considered by analysis of variance and of covariance on final body weight, separately for males and females. Analyses were carried separately for main study and additional group 5 and 6 animals. Unbiased estimates of differences from control were provided by the difference between each treatment group least-squares mean and the control group least-squares mean. Differences from control were tested statistically by comparing each treatment group least-squares mean with the control group least squares mean using a two-sided Student's t-test, based on the error mean square in the analysis.
- Clinical signs:
- effects observed, treatment-related
- Mortality:
- mortality observed, treatment-related
- Body weight and weight changes:
- effects observed, treatment-related
- Food consumption and compound intake (if feeding study):
- effects observed, treatment-related
- Food efficiency:
- not examined
- Water consumption and compound intake (if drinking water study):
- not examined
- Ophthalmological findings:
- not examined
- Haematological findings:
- no effects observed
- Clinical biochemistry findings:
- effects observed, treatment-related
- Urinalysis findings:
- not examined
- Behaviour (functional findings):
- not examined
- Organ weight findings including organ / body weight ratios:
- effects observed, treatment-related
- Gross pathological findings:
- effects observed, treatment-related
- Histopathological findings: non-neoplastic:
- effects observed, treatment-related
- Histopathological findings: neoplastic:
- no effects observed
- Details on results:
- Clinical signs were seen in animals exposed to 10.3 ppm and greater and in general the number and severity of these clinical signs increased with repeated exposure at low doses, whereas the onset of clinical signs was earlier at higher doses but also a certain degree of recovery from symptoms was seen at higher doses. Signs included reddening of the nose, stains around the snout, stains around the mouth, signs of salivation, signs of respiratory tract irritation, irregular breathing, signs of urinary incontinence, piloerection, chomodacryorrhoea, hunched posture, increased response to touch, thin appearance. Some evidence of recovery from these symptoms was seen during periods of non-exposure. Body weights gradually decreased in males exposed to 23.3 ppm and in males and females exposed to 58.1/27.3 ppm. Food consumption was affected in males exposed to 23.3 ppm and in males and females exposed to 58.1/27.3 ppm. Minor effects on haematology were seen at exposure levels of 23.3 ppm, which were considered as not biologically and toxicologically significant. In both sexes there was a minimal decrease in albumin and total protein levels at 23.3 ppm exposure. Kidney weight was increased in females exposed to 23.3 ppm and lung/body weight ratio in males and kidney/body weight ratios in females exposed to 23.3 ppm was increased. Treatment-related findings were seen in the nasal and oral cavities of rats at the necropsy following termination of the study. Staining of the nares was seen at 10 ppm and above and mouth staining was at 25 ppm. In both instances, no dose-response could be found. Increased incidences of findings in exposed animals over controls during the microscopic examinations were seen in the nasal cavity, larynx and lung including necrosis, inflammation and perivascular neutrophil infiltration.
- Key result
- Dose descriptor:
- NOAEL
- Effect level:
- 2.9 mg/m³ air
- Sex:
- male/female
- Basis for effect level:
- histopathology: non-neoplastic
- Dose descriptor:
- LOAEL
- Effect level:
- 14.6 mg/m³ air
- Sex:
- male/female
- Basis for effect level:
- histopathology: non-neoplastic
- Key result
- Critical effects observed:
- no
- Conclusions:
- Whole body exposure to hydrogen peroxide vapour for 6 hours per day, 5 days per week for a period of 28 days at concentrations of 2.03, 10.3 or 23.3 ppm resulted in signs of general toxicity in males exposed to 23.3 ppm and were consistent with the material being a respiratory tract irritant. Treatment-related microscopic changes were seen in the nasal cavity in animals exposed to 10.3 ppm or above. The no observed effect level (NOEL) for the study was considered to be 2.03 ppm hydrogen peroxide.
- Executive summary:
A repeated dose inhalation toxicity study was performed with male and female Alpk:APfSD (Wistar-derived) rats exposed to hydrogen peroxide vapours for 6 hours per day, 5 days per week for a period of 28 days at concentrations of 2.03, 10.3 or 23.3 ppm. The study was carried out under GLP conditions and in accordance with OECD Guideline No. 412. Treatment of a group exposed initially to 58.1 ppm and subsequently to 27.3 ppm was terminated before schedule due to the toxicity of the test material. Clinical observations were consistent with the material being a respiratory tract irritant (reddened noses, stains around the nose, abnormal respiratory noise) and in general the time to onset, incidence and severity of clinical signs increased with exposure concentration and repeated exposure. Males exposed to 23.3 ppm hydrogen peroxide showed lower food consumption and body weight gain compared to controls. Minimal changes in albumin and total protein blood levels were found in males and females exposed to 23.3 ppm. Histopathological, treatment-related changes were seen in the anterior-most regions of the nasal cavity lined with squamous epithelium, where minimal to slight necrosis (with associated inflammation) and rhinitis were seen in animals exposed to 10.3 and 23.3 ppm hydrogen peroxide. Inflammation and epithelial erosion in the larynx and increased perivascular neutrophil infiltration in the lungs were considered unlikely to be related to treatment in the absence of a clear dose response relationship. The no observed effect level (NOEL) for the study was considered to be 2.03 ppm hydrogen peroxide (corresponding to 2.9 mg/m3).
Reference
Table 1: Results of the clinical chemistry haematology
Parameter changed |
Control group 1 (0 ppm) |
2 ppm |
10 ppm |
Control group 2 (0 ppm)A |
25 ppmA |
Males |
|
|
|
|
|
Mean cell volume (fl) |
56.1 |
56.2 |
56.0 |
55.3 |
55.3* |
Mean cell haemoglobin (pg) |
19.4 |
19.6 |
19.4 |
19.0 |
18.8* |
Albumin (g/L) |
33.6 |
32.8 |
33.1 |
32.7 |
31.3* |
Total protein (g/L) |
66. |
64.9 |
65.1 |
63.3 |
57.8** |
Females |
|
|
|
|
|
Red blood cell count (10e12/L) |
7.56 |
7.72 |
7.42 |
7.77 |
7.43* |
Albumin (g/L) |
33.2 |
33.0 |
32.8 |
32.6 |
31.3* |
Total protein (g/L) |
61.1 |
61.3 |
60.2 |
61.4 |
57.0* |
Glucose (mmol/L) |
12.4 |
13.7 |
12.9 |
12.8 |
9.6** |
A) 25 ppm group is compared to control group 2 since animals were treated simultaneously. *p <0.05, **p <0.01 (student's t-test, two-sided)
Table 2: Microscopic findings
Target organs |
Control (0 ppm) |
2 ppm |
10 ppm |
25 ppm |
Nasal cavity |
No finding |
No finding |
Necrosis and inflammation (sqamous epithelium, anterior region of nasal cavity) 3/5 males, 2/5 females |
Rhinitis 1/5 males Necrosis and inflammation (sqamous epithelium, anterior regions of nasal cavity) 4/5 males, 4/5 females |
Larynx |
No finding |
Inflammation 1/5 females |
No finding |
Mononuclear cell infiltration 2/5 females Epithelia erosion 1/5 males |
Lung |
No finding |
Increase in perivascular neurophil infiltration 1/5 males Haemorrhage 2/5 males, 1/5 females |
Increase in perivascular neurophil infiltration 1/5 males Haemorrhage 2/5 males |
Increase in perivascular neurophil infiltration 1/5 males, 2/5 females |
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed
Repeated dose toxicity: inhalation - local effects
Link to relevant study records
- Endpoint:
- short-term repeated dose toxicity: inhalation
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- other: The study was carried out in accordance with the respective OECD Guidelines and under GLP conditions. No deviations were reported that were likely to negatively influence the outcomes of the study.
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 412 (Subacute Inhalation Toxicity: 28-Day Study)
- Deviations:
- no
- GLP compliance:
- yes
- Limit test:
- no
- Species:
- rat
- Strain:
- other: Alpk:ApfSD (Wistar derived)
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Rodent Breeding Unit, Alderley Park, Macclesfield, UK
- Age at study initiation: 6 to 7 weeks
- Weight at study initiation: for groups 1-4, 242.5 +/- 9.6 g (males), 190.2 +/- 12.3 g (females); four groups five and six, 300.3 +/- 9.1 g (males), 233.8 +/- 11.0 g (females)
- Fasting period before study:
- Housing: five rats, sexes separately, in stainless steel cages
- Diet (e.g. ad libitum): CT1 supplied by Special Diet Services Ltd, Witham, UK ad libitum
- Water (e.g. ad libitum): mains water ad libitum
- Acclimation period: 5 days
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 30-70
- Air changes (per hr): at least 15
- Photoperiod (hrs dark / hrs light): 12 hours light/12 hours darkness - Route of administration:
- inhalation
- Type of inhalation exposure:
- whole body
- Vehicle:
- other: unchanged (no vehicle)
- Remarks on MMAD:
- MMAD / GSD: not applicable
- Details on inhalation exposure:
- Test atmospheres were generated using a glass concentric-jet atomiser to generate fine aerosol directly into a 3-necked quick-fit round bottomed flask, heated by placing it in a waterbath at 80 °C. The test substance was pumped to the atomiser using a peristaltic pump, typically operating at a pump speed giving a flow rate of test material of approximately 1 mL/min. Clean, dry air was passed through the atomiser at nominal flow rates of 2, 10 or 15 L/minute for groups 2, 3 and 4 respectively, and (together with heated generation air at 25 L/minute) carried the atmosphere to the lng term exposure chamber. Diluting air was added directly to the exposure chambers at a flow rate of 500-600 L/min. Air flows were monitored continuously using variable area flowmeters.
- Analytical verification of doses or concentrations:
- yes
- Details on analytical verification of doses or concentrations:
- Test atmospheres were sampled by passing the atmosphere, at a fixed flow rate for a known time period, through a known volume of de-ionised water in a midget impinger. The resulting solutions were analysed by flow injection analysis using a LC Module 1 (Waters) separations module at a flow rate of 5 L/minute, a dilute Cobalt-bicarbonate reagent mobile phase, and a 486 series UV detector (Waters) at 260 nm. The limit of detection of the method was assessed to be approximately 0.1 mg/mL corresponding to an atmosphere concentration of 0.1 ppm.
- Duration of treatment / exposure:
- 28 days
- Frequency of treatment:
- 6 hours daily, 5 days per week
- Remarks:
- Doses / Concentrations:
2.03, 10.3, 23.3, 58.1/27.3 ppm (2.88, 14.6, 33, 82.4/38.7 mg/m3)
Basis:
analytical conc. - No. of animals per sex per dose:
- five males, five females
- Control animals:
- yes
- Details on study design:
- Another group (group 4 of the main test) of animals was exposed to 60 ppm at day 1, 4, 5 and 6. Thereafter, the exposure level was reduced to 30 ppm at day 11 and 12. The treatment was terminated on day 13 and animals were sacrificed due to toxicity. The group treated with a target concentration of 25 ppm was introduced later in the test after termination of the test group 4 (60/30 ppm).
- Observations and examinations performed and frequency:
- Clinical observations: prior to the start of the study, frequently during exposure and at the end of the 6 hour exposure duration, daily before exposure
Body weight: before study initiation, weekly during exposure study
Food consumption: continuously throughout the study
Clinical pathology (haematology, blood clinical chemistry): at termination of study - Sacrifice and pathology:
- Animals were killed by an overdose of halothane Ph. Eur. vapour followed by exsanguination. Weights of adrenal glands, kidneys, liver, lungs and testes were measured. All animals were subjected to full examination post mortem including external and careful internal examination of all organs and structures. Slides were prepared from various organs and tissues. All submitted tissues from control and high exposure animals together with the lungs, liver, kidney, trachea, nasal passages and abnormal tissues from the low and mid exposure groups were routinely processed, embedded in paraffin wax, sectioned at 5 micrometre and stained with haematoxylin and eosin. Examination by light microscopy was performed for these tissues.
- Statistics:
- Body weights were considered by analysis of covariance on initial body weight, separately for males and females. Haematology and blood clinical chemistry were considered by analysis of variance. Male and female data were analysed together. Organ weights were considered by analysis of variance and of covariance on final body weight, separately for males and females. Analyses were carried separately for main study and additional group 5 and 6 animals. Unbiased estimates of differences from control were provided by the difference between each treatment group least-squares mean and the control group least-squares mean. Differences from control were tested statistically by comparing each treatment group least-squares mean with the control group least squares mean using a two-sided Student's t-test, based on the error mean square in the analysis.
- Clinical signs:
- effects observed, treatment-related
- Mortality:
- mortality observed, treatment-related
- Body weight and weight changes:
- effects observed, treatment-related
- Food consumption and compound intake (if feeding study):
- effects observed, treatment-related
- Food efficiency:
- not examined
- Water consumption and compound intake (if drinking water study):
- not examined
- Ophthalmological findings:
- not examined
- Haematological findings:
- no effects observed
- Clinical biochemistry findings:
- effects observed, treatment-related
- Urinalysis findings:
- not examined
- Behaviour (functional findings):
- not examined
- Organ weight findings including organ / body weight ratios:
- effects observed, treatment-related
- Gross pathological findings:
- effects observed, treatment-related
- Histopathological findings: non-neoplastic:
- effects observed, treatment-related
- Histopathological findings: neoplastic:
- no effects observed
- Details on results:
- Clinical signs were seen in animals exposed to 10.3 ppm and greater and in general the number and severity of these clinical signs increased with repeated exposure at low doses, whereas the onset of clinical signs was earlier at higher doses but also a certain degree of recovery from symptoms was seen at higher doses. Signs included reddening of the nose, stains around the snout, stains around the mouth, signs of salivation, signs of respiratory tract irritation, irregular breathing, signs of urinary incontinence, piloerection, chomodacryorrhoea, hunched posture, increased response to touch, thin appearance. Some evidence of recovery from these symptoms was seen during periods of non-exposure. Body weights gradually decreased in males exposed to 23.3 ppm and in males and females exposed to 58.1/27.3 ppm. Food consumption was affected in males exposed to 23.3 ppm and in males and females exposed to 58.1/27.3 ppm. Minor effects on haematology were seen at exposure levels of 23.3 ppm, which were considered as not biologically and toxicologically significant. In both sexes there was a minimal decrease in albumin and total protein levels at 23.3 ppm exposure. Kidney weight was increased in females exposed to 23.3 ppm and lung/body weight ratio in males and kidney/body weight ratios in females exposed to 23.3 ppm was increased. Treatment-related findings were seen in the nasal and oral cavities of rats at the necropsy following termination of the study. Staining of the nares was seen at 10 ppm and above and mouth staining was at 25 ppm. In both instances, no dose-response could be found. Increased incidences of findings in exposed animals over controls during the microscopic examinations were seen in the nasal cavity, larynx and lung including necrosis, inflammation and perivascular neutrophil infiltration.
- Key result
- Dose descriptor:
- NOAEL
- Effect level:
- 2.9 mg/m³ air
- Sex:
- male/female
- Basis for effect level:
- histopathology: non-neoplastic
- Dose descriptor:
- LOAEL
- Effect level:
- 14.6 mg/m³ air
- Sex:
- male/female
- Basis for effect level:
- histopathology: non-neoplastic
- Key result
- Critical effects observed:
- no
- Conclusions:
- Whole body exposure to hydrogen peroxide vapour for 6 hours per day, 5 days per week for a period of 28 days at concentrations of 2.03, 10.3 or 23.3 ppm resulted in signs of general toxicity in males exposed to 23.3 ppm and were consistent with the material being a respiratory tract irritant. Treatment-related microscopic changes were seen in the nasal cavity in animals exposed to 10.3 ppm or above. The no observed effect level (NOEL) for the study was considered to be 2.03 ppm hydrogen peroxide.
- Executive summary:
A repeated dose inhalation toxicity study was performed with male and female Alpk:APfSD (Wistar-derived) rats exposed to hydrogen peroxide vapours for 6 hours per day, 5 days per week for a period of 28 days at concentrations of 2.03, 10.3 or 23.3 ppm. The study was carried out under GLP conditions and in accordance with OECD Guideline No. 412. Treatment of a group exposed initially to 58.1 ppm and subsequently to 27.3 ppm was terminated before schedule due to the toxicity of the test material. Clinical observations were consistent with the material being a respiratory tract irritant (reddened noses, stains around the nose, abnormal respiratory noise) and in general the time to onset, incidence and severity of clinical signs increased with exposure concentration and repeated exposure. Males exposed to 23.3 ppm hydrogen peroxide showed lower food consumption and body weight gain compared to controls. Minimal changes in albumin and total protein blood levels were found in males and females exposed to 23.3 ppm. Histopathological, treatment-related changes were seen in the anterior-most regions of the nasal cavity lined with squamous epithelium, where minimal to slight necrosis (with associated inflammation) and rhinitis were seen in animals exposed to 10.3 and 23.3 ppm hydrogen peroxide. Inflammation and epithelial erosion in the larynx and increased perivascular neutrophil infiltration in the lungs were considered unlikely to be related to treatment in the absence of a clear dose response relationship. The no observed effect level (NOEL) for the study was considered to be 2.03 ppm hydrogen peroxide (corresponding to 2.9 mg/m3).
Reference
Table 1: Results of the clinical chemistry haematology
Parameter changed |
Control group 1 (0 ppm) |
2 ppm |
10 ppm |
Control group 2 (0 ppm)A |
25 ppmA |
Males |
|
|
|
|
|
Mean cell volume (fl) |
56.1 |
56.2 |
56.0 |
55.3 |
55.3* |
Mean cell haemoglobin (pg) |
19.4 |
19.6 |
19.4 |
19.0 |
18.8* |
Albumin (g/L) |
33.6 |
32.8 |
33.1 |
32.7 |
31.3* |
Total protein (g/L) |
66. |
64.9 |
65.1 |
63.3 |
57.8** |
Females |
|
|
|
|
|
Red blood cell count (10e12/L) |
7.56 |
7.72 |
7.42 |
7.77 |
7.43* |
Albumin (g/L) |
33.2 |
33.0 |
32.8 |
32.6 |
31.3* |
Total protein (g/L) |
61.1 |
61.3 |
60.2 |
61.4 |
57.0* |
Glucose (mmol/L) |
12.4 |
13.7 |
12.9 |
12.8 |
9.6** |
A) 25 ppm group is compared to control group 2 since animals were treated simultaneously. *p <0.05, **p <0.01 (student's t-test, two-sided)
Table 2: Microscopic findings
Target organs |
Control (0 ppm) |
2 ppm |
10 ppm |
25 ppm |
Nasal cavity |
No finding |
No finding |
Necrosis and inflammation (sqamous epithelium, anterior region of nasal cavity) 3/5 males, 2/5 females |
Rhinitis 1/5 males Necrosis and inflammation (sqamous epithelium, anterior regions of nasal cavity) 4/5 males, 4/5 females |
Larynx |
No finding |
Inflammation 1/5 females |
No finding |
Mononuclear cell infiltration 2/5 females Epithelia erosion 1/5 males |
Lung |
No finding |
Increase in perivascular neurophil infiltration 1/5 males Haemorrhage 2/5 males, 1/5 females |
Increase in perivascular neurophil infiltration 1/5 males Haemorrhage 2/5 males |
Increase in perivascular neurophil infiltration 1/5 males, 2/5 females |
Endpoint conclusion
- Endpoint conclusion:
- adverse effect observed
- Dose descriptor:
- NOAEC
- 2.9 mg/m³
- Study duration:
- subacute
- Species:
- rat
- Quality of whole database:
- One key studies available of Klimish score = 1.
Repeated dose toxicity: dermal - systemic effects
Endpoint conclusion
- Endpoint conclusion:
- no study available
Repeated dose toxicity: dermal - local effects
Endpoint conclusion
- Endpoint conclusion:
- no study available
Mode of Action Analysis / Human Relevance Framework
Calcium peroxide when in contact with water, on the one hand hydrolyses into hydrogen peroxide, and on the other hand results in a loss of active oxygen.
CaO2 + H2O → CaO + H2O2
2CaO2→ 2CaO + O2
2CaO2+ 2H2O → 2Ca2++ 4OH- + O2
The toxicity of the reaction mass is due to the hydrolysis product hydrogen peroxide (H2O2) and calcium hydroxide (Ca(OH)2). Under physiological conditions, calcium hydroxide ultimately dissociates into calcium cations (Ca2 +) and hydroxyl anions (OH-). Calcium, is an essential and abundantly available mineral nutrient. Hydroxyl anion is neutralised in body fluids.
Additional information
Repeated dose toxicity - oral:
Hydrogen peroxide:
A reliable, well-conducted 90-day study with a catalase deficient strain of mice found a decrease in body weight at doses of 3000 ppm in drinking water (Freeman 1997). The study indicated that the NOAEL of hydrogen peroxide in drinking water was 100 ppm implying a daily dose of 26 mg/kg bw for males and 37 mg/kg bw for females. The LOAEL was 300 ppm (76 mg/kg bw for males, 103 mg/kg bw for females) based on dose-related reductions in food and water consumption and on the observation of duodenal mucosal hyperplasia in one male. Hyperplasia was a consistent finding at the higher levels of 1,000 and 3,000 ppm both in males and females (corresponding daily doses were 239 mg/kg for males, 328 mg/kg for females and 547 mg/kg for males, 785 mg/kg for females, respectively), and it was completely reversible in the recovery period. At the top dose (3,000 ppm) plasma total protein and globulin concentrations were reduced.
Calcium lactate:
A reliable, well-conducted 2 years combined chronic toxicity/carcinogenicity study, concluded that calcium lactate had neither toxic nor carcinogenic activity in F344 rats when it was given continuously in the drinking-water. In females, the mortality rate in the 5% group was slightly higher than those in the other two groups. This difference, however, was not significant. Throughout the administration period, there was a dose-dependent inhibitory effect of calcium lactate on the growth of rats of both sexes. Compared with the controls, a 13% decrease in body-weight gain was observed in male and female rats of the high-dose group. No specific dose-related changes were observed in any of the haematological and biochemical parameters. Increase in hyperplasias/pheochromocytomas of male rats in the high-dose group was probably due to experimental variability and not related to treatment with calcium lactate. No clear toxic lesions specifically caused by long-term administration of calcium lactate, except for the slight calcium deposition in the renal papilla, were detected in any organ. The type of lesion observed in the kidney of female rats in the 5% group was histologically different from the so-called nephrocalcinosis, which is characterized by an intraluminal deposition of calcium observed mainly in the cortico-medullary region. The pathogenesis of this lesion is unclear and might depend on the increase in the urinary calcium level. The observed increase in relative brain weights of males and females in the high-dose group may result from the decrease in body-weight gains and not to the toxic effect of calcium lactate. Based on these results, the NOAEL for both chronic toxicity and carcinogenicity was determined to be 5% drinking water, i.e. 2150 and 2280 mg/kg bw/day to male and female rats respectively, corresponding to 279.5 and 296.4 mgCa/kg bw/day (860 and 570 mgCa/rat).
Repeated dose toxicity - inhalation:
Hydrogen peroxide:
A reliable 28-day repeated dose inhalation toxicity study was performed with male and female Alpk:APfSD (Wistar-derived) rats exposed to hydrogen peroxide vapours for 6 hours per day, 5 days per week at concentrations of 2.03, 10.3 or 23.3 ppm (Kilgour 2002). The study was carried out under GLP conditions and in accordance with OECD Guideline No. 412. Treatment of a group exposed initially to 58.1 ppm and subsequently to 27.3 ppm was terminated before schedule due to the toxicity of the test material. Clinical observations were consistent with the material being a respiratory tract irritant (reddened noses, stains around the nose, abnormal respiratory noise) and in general the time to onset, incidence and severity of clinical signs increased with exposure concentration and repeated exposure. Males exposed to 23.3 ppm hydrogen peroxide showed lower food consumption and body weight gain compared to controls. Minimal changes in albumin and total protein blood levels were found in males and females exposed to 23.3 ppm. Histopathological, treatment-related changes were seen in the anterior-most regions of the nasal cavity lined with squamous epithelium, where minimal to slight necrosis (with associated inflammation) and rhinitis were seen in animals exposed to 10.3 and 23.3 ppm hydrogen peroxide. Inflammation and epithelial erosion in the larynx and increased perivascular neutrophil infiltration in the lungs were considered unlikely to be related to treatment in the absence of a clear dose response relationship. The no observed effect level (NOEL) for the study was considered to be 2.03 ppm hydrogen peroxide (corresponding to 2.9 mg/m3).
Justification for classification or non-classification
Based on available data, the substance is not classified for repeated dose toxicity according to the CLP Regulation (EC) no. 1272/2008. Hydrogen peroxide should not be classified for systemic effects as it is not systemically available and as the substance exhibits only local irritancy.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.