[3aR-(3aα,5aβ,9aα,9bβ)]decahydro-3a,6,6,9a-tetramethylnaphth[2,1-b]furan-2(1H)-one

Particle size distribution (Granulometry)

Administrative data

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016-12-16

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

The study was conducted similarly to EU guideline, with minor deviations. Test substance is adequately characterised with its purity. However, as a single measurement was performed, intra and inter batch variation were not assessed, and sample preparation is unclear. Therefore validity applies with restrictions.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

other: EUR 20268 EN: Guidance Document on the Determination of Particle Size Distribution, Fibre Length and Diameter Distribution of chemical substances (European Commission, 2002)

Deviations:

yes

Remarks:

no microscope observation; no preliminary screening test at 100 μm

GLP compliance:

no

Type of method:

Laser scattering/diffraction

Type of particle tested:

primary particle

Type of distribution:

volumetric distribution

Test material

Test material information

Constituent 1

Reference substance name:

[3aR-(3aα,5aβ,9aα,9bβ)]decahydro-3a,6,6,9a-tetramethylnaphth[2,1-b]furan-2(1H)-one

EC Number:

209-269-0

EC Name:

[3aR-(3aα,5aβ,9aα,9bβ)]decahydro-3a,6,6,9a-tetramethylnaphth[2,1-b]furan-2(1H)-one

Cas Number:

564-20-5

Molecular formula:

C16H26O2

IUPAC Name:

[3aR-(3aα,5aβ,9aα,9bβ)]decahydro-3a,6,6,9a-tetramethylnaphth[2,1-b]furan-2(1H)-one

Test material form:

solid: crystalline

Details on test material:

Appearance: white, shiny, crystals

Results and discussion

Mass median aerodynamic diameter:

>= 59 - <= 77 µm

Particle size distribution at different passages

No.:

#1

Size:

< 105 µm

Distribution:

>= 64 - <= 74 %

Any other information on results incl. tables

The sample selection or preparation is unclear. It is supposed below that samples with particles < 850 µm relate to a sieved fraction, i.e. worst-case for inhalation potential.

From the curves, the distribution of particles <850 µm shows three peaks, a major one at ca 90 µm, and two secondary at ca 30 and 200 µm.

Results for particle size corresponding to 10, 50 and 90% of distribution, % corresponding to the inhalable, thoracic and respirable fractions (resp. < 100, 10 and 4 µm), are given in the table below.

Also, a threshold of 500 μm is generally assumed to be of concern for dust explosion potential.

Batch	D10 (µm)	D50 (µm)	D90 (µm)	< 105 µm	< 11 µm	< 4.5 µm	< 515 µm
1003103814-46 with particles < 850μm	16	77	218	64%	6.1%	1.7%	100%
1003103814-46 with particles > 850μm (*)	144	754	851	8.8%	3.2%	1.5%	21%
1003107355-46 with particles < 850μm	12	59	170	74%	8.3%	2.3%	100%
1003107355-46 with particles > 850μm (*)	113	779	856	9.3%	3.8%	1.6%	14%

(*) these values are not representative of this sample because particles are higher of the maximum measuring range of the apparatus (875 micron).

Applicant's summary and conclusion

Conclusions:

The test substance contains a limited fraction of particles fine enough to be inhaled and reach the thoracic fraction.
Dust explosion potential cannot be excluded.

Executive summary:

Particle size distribution of two different batches of test substance was measured with laser granulometry.

Samples with particles > 850 µm were partly out of the measuring range of the apparatus. On the fine fraction (particles < 850 µm), ca 70% are of inhalable size (<100µm), but only ca 2% reach the lung alveoli; dust explosion potential cannot be excluded either.