Reaction mass of Magnesium peroxide and magnesium carbonate and magnesium hydroxide and magnesium oxide

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: The study was carried out in compliance with GLP and US-EPA Vol 50 (§798.1150) Guideline, which is equivalent to OECD Guideline No. 403.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: US-EPA Vol 50 (§798.1150)

GLP compliance:

yes

Test type:

standard acute method

Test material

Test material information

Constituent 1

Reference substance name:

Hydrogen peroxide

EC Number:

231-765-0

EC Name:

Hydrogen peroxide

Cas Number:

7722-84-1

Molecular formula:

H2O2

IUPAC Name:

hydrogen peroxide

Details on test material:

Hydrogen peroxide, 50% w/w

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc. Raleigh, North Carolina
- Age at study initiation: 8-9 weeks;
- Weight at study initiation: males: 262 - 277 g; females 217 – 257 g
- Fasting period before study:
- Housing: Doubly in suspended, stainless steel, wire mash cages during acclimation and non-exposure period; individually in 100 litre Plexiglass exposure chambers during exposure
- Diet (e.g. ad libitum): Purina Rodent Laboratory Chow Brand Animal Diet #5001 ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: All animals were acclimated for 11 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-25 °C; 25 °C (during exposure)
- Humidity (%): 17-60 % (40-44 % during exposure)
- Air changes (per hr): No data
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

inhalation

Type of inhalation exposure:

whole body

Vehicle:

other: no data

Details on inhalation exposure:

The atmosphere was generated by bubbling air flow through a reservoir containing 1000 ml of 50% hydrogen peroxide. Particle size distribution measurements showed a particulate level of 0.020 mg/m3, which was comparable to background air levels thus indicating no appreciable aerosol formation.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

Samples for colorimetric determination of vapours of hydrogen peroxide (50 %) were withdrawn once per hour

Duration of exposure:

4 h

Concentrations:

Nominal concentration: 7.7 [mg/L]
Analytical concentration: 0.17 [mg/L] (maximum attainable vapour)

No. of animals per sex per dose:

5 rats

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: yes/no
- Other examinations performed: clinical signs, body weight,organ weights, histopathology

Statistics:

no data

Results and discussion

Preliminary study:

none

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 170 mg/m³ air

Exp. duration:

4 h

Mortality:

No deaths occurred.

Clinical signs:

other: Observations noted during exposure included decreased activity and eye closure. Signs exhibited by animals upon removal from the chamber and during the two-hour post-exposure observation period on Day 1 included nasal discharge, excessive salivation and a

Body weight:

Body weight at day 2 was slightly less than pre-test value. Recovery of weight occurred thereafter and all animals were in excess of their pre-exposure body weight by termination of the study.

Gross pathology:

No effects considered treatment-related were found. Lung weights were comparable to historical values

Other findings:

no other findings

Any other information on results incl. tables

none

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Classification according to Directive 2001/59/EC (adaptation of 67/548/EEC) is not necessary since at the maximum technical attainable vapour concentration of 0.17 mg/L no deaths occurred.

Executive summary:

The acute inhalation toxicity of hydrogen peroxide (50 %) aerosols was tested in male and female Sprague-Dawley rats according to US EPA Guideline Vol 50 (§798.1150). Animals received a single 4 -hour whole-body exposure to the maximum attainable aerosol concentration of 170 mg/m³. All tested animals survived the exposure and subsequent 14 -day post-exposure observation period. Signs of treatment were minimal during the exposure but a few responses such as nasal discharge were noted during the whole 14 -day observation period. A minimal, transient adverse effect upon body weight was produced by treatment. Otherwise, body weight gain was considered unremarkable. Gross post mortem observations and lung weights were considered unremarkable. No LD₅₀ value for acute inhalation toxicity could be established and the LD₅₀ value must be greater than the attainable aerosol concentration of hydrogen peroxide of 170 mg/m³.