Registration Dossier

Diss Factsheets

Administrative data

Endpoint:
health surveillance data
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
no data available
Reliability:
other: high
Rationale for reliability incl. deficiencies:
other: Well documented publication.

Data source

Reference
Reference Type:
publication
Title:
Human pulmonary responses to experimental inhalation of high concentration fine and ultrafine magnesium oxide particles
Author:
Kuschner, W.G.; et al.
Year:
1997
Bibliographic source:
Environ. Health Perspectives, Vol. 105, No. 11: 1234-1237.

Materials and methods

Study type:
medical monitoring
Endpoint addressed:
acute toxicity: inhalation
respiratory irritation
Test guideline
Qualifier:
no guideline available
Principles of method if other than guideline:
Characterisation of human pulmonary responses to controlled experimental high-dose exposure to fine and ultrafine magnesium oxide particles.
GLP compliance:
no

Test material

Constituent 1
Reference substance name:
Magnesium oxide
EC Number:
215-171-9
EC Name:
Magnesium oxide
IUPAC Name:
215-171-9
Constituent 2
Reference substance name:
1309-48-4
Cas Number:
1309-48-4
IUPAC Name:
1309-48-4
Constituent 3
Reference substance name:
magnesium oxide
IUPAC Name:
magnesium oxide
Test material form:
not specified
Details on test material:
- Name of test material (as cited in study report): Magnesium oxide dust
No further details are given.

Method

Type of population:
general
Ethical approval:
not specified
Details on study design:
Subjects: 6 healthy volunteers, 4 male and 2 female subjects, 3 smokers and 3 non-smokers, aged between 21 and 43.
Treatment: Inhalation of fine and ultrafine magnesium oxide particles produced from a furnace system model. Individual exposure concentrations were (duration in parentheses) 5.8 (45 min), 230 (15 min), 210 (20 min), 123 (45 min), 110 (45 min), and 143 (45 min) mg/m³, given as MgO. By weight, 28 % of the fume particles were ultrafine (<0.1 µm in diameter) and over 98 % of fume particles were fine (<2.5 µm in diameter).
Subjects inhaled magnesium oxide fume with medical-grade air through a mouth-breathing face mask.
Observations: 18 to 20 hours after inhalation, bronchoalveolar lavage (BAL) cell and cytokine concentrations, pulmonary function and peripheral blood neutrophil concentrations were quantified. Post-exposure studies were compared with control studies from the same 6 subjects.

Results and discussion

Results:
Over 98% of fume particles were fine or ultrafine and 98.6 % were less than 1.8 µm in diameter.
There were no significant differences in BAL inflammatory cell concentrations, BAL interleukin (IL)-1, IL-6, IL-8, tumour necrosis factor, pulmonary function or peripheral blood neutrophil concentrations compared with controls.
The high-dose fine and ultrafine magnesium oxide particle exposure did not produce a measurable pulmonary inflammatory response.
None of the test persons reported any exposure-related symptoms.

Applicant's summary and conclusion

Conclusions:
It was concluded that fine and ultrafine particle inhalation (MgO) do not result in toxicity in a generic manner independent of particle composition. The findings support the concept that particle chemical composition, in addition to particle size, is an important determinant of respiratory effects.

Categories Display