4,4'-methylenebis(2,6-xylidine)

Particle size distribution (Granulometry)

Link to relevant study record(s)

Reference

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

november 15th 2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Justification for type of information:

The study was conducted according to a EU guideline study. No deviation affected the quality of the study. The substance is considered to be adequately characterised. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 110 (Particle Size Distribution / Fibre Length and Diameter Distributions - Method A: Particle Size Distribution (effective hydrodynamic radius)

Version / remarks:

1981

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7520 (Particle Size, Fiber Length, and Diameter Distribution)

Version / remarks:

1996

Qualifier:

according to guideline

Guideline:

ISO 13320 (Particle size analysis - Laser diffraction methods)

Version / remarks:

2009

Principles of method if other than guideline:

The particle size distribution is determined using laser diffraction. As measuring device, a Malvern Mastersizer 2000 is used. The powder is brought via a powder dispersing cell Scirocco 2000 into the laser light beam and the diffraction pattern is determined. From the diffraction pattern the particle size distribution is calculated.

GLP compliance:

yes (incl. QA statement)

Remarks:

(inspected on 11 & 12 October 2016 / signed on 28 Feb. 2017)

Type of method:

Laser scattering/diffraction

Type of particle tested:

other: powder

Type of distribution:

volumetric distribution

Percentile:

D10

Mean:

5.7 µm

St. dev.:

0.1

Percentile:

D50

Mean:

97.7 µm

St. dev.:

3.7

Percentile:

D90

Mean:

541.2 µm

St. dev.:

34.1

No.:

#1

Size:

< 500 µm

Distribution:

88.5 %

No.:

#2

Size:

< 100 µm

Distribution:

50.5 %

No.:

#3

Size:

< 10 µm

Distribution:

18 %

No.:

#4

Size:

< 4 µm

Distribution:

6.5 %

Result

Light Microscopy

The optically investigation of the test item with different magnifications is shown in Figure1 in the experimental report. For a better visualization a 10x10 grid with 100 µm squares was used. At all three magnifications agglomerates can be observed.

Particle Size Distribution

Two test series of 3 measurements each were performed with the test item.From each 3-fold measurement anaverage value wascalculated.The final result was calculated as mean value from the average values of the two samples.

 

Test series 1	D10 (µm)	D50 (Median diameter, µm)	D90 (µm)
Test 1	5.7	101.9	579.3
Test 2	5.6	96.8	511.7
Test 3	5.5	94.7	537.2
Averaged	5.6	97.8	542.0

 

Test series 2	D10 (µm)	D50 (Median diameter, µm)	D90 (µm)
Test 1	5.7	96.8	535.8
Test 2	5.8	101.5	541.6
Test 3	5.6	94.5	544.3
Averaged	5.7	97.6	540.4

Test series 1:

D₁₀:       5.6 µm

D₅₀:       97.8 µm (Median diameter)

D₉₀:       542.0 µm

Test series 2 :

D₁₀:       5.7 µm

D₅₀:       97.6 µm (Median diameter)

D₉₀:       540.4 µm

Average

D₁₀:       5.7 µm

D₅₀:       97.7 µm (Median diameter

D₉₀:    541.2 µm

The results in Volume % passing at 4, 10, 100 and 500 µm:

Particle size (µm)	Volume under (%) / Average 1	Volume under (%) / Average 2	Volume under (%) / Mean
4	6.5	6.4	6.5
10	18.0	17.9	18.0
100	50.4	50.5	50.5
500	88.5	88.5	88.5

Conclusions:

The test substance contains a limited fraction of particles fine enough to be inhaled and reach the thoracic fraction.
Dust explosion potential should be considered.

Executive summary:

The granulometry of the test substance was determined under GLP according to ISO13320 and OECD 110 guidelines, with laser diffraction method, in air.

The distribution was a non-symetric Gaussian curve, with a median diameter of 97.7 µm.

With regard to inhalation potential, about 50.5% of total particles are smaller than 100 µm, ca 18.0% could reach the thoracic fraction (<10 µm) and ca 6.5% are lower than 4µm.

Fine particles relevant to dust explosion hazard (<500 µm) account for 88.5%.

Description of key information

Median diameter (D50) = 97.7 µm

Respirable fraction (<4µm) = 6.5%

Thoracic fraction (<10 µm) = 18.0%

Inhalable fraction (<100 µm) = 50.5%

Dust particles (<500 µm) = 88.5 % (dust explosion potential)

Additional information

A reliable experimental study, conducted according to a recognized OECD/ISO guideline, and under GLP, is available. Despite minor restrictions due to measurement of a single batch, it is considered as a key study.