Sodium dichromate

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:

2009-08-11 to 2009-08-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Qualifier:

according to guideline

Guideline:

other: DIN ISO 4497

Deviations:

no

Principles of method if other than guideline:

The dry sieve test is performed according to DIN ISO 4497 using a 1mm and 100 µm sieve to separate bigger particles (>1 mm) from smaller particles and the particulate matter (<100 ). Laser diffraction of the particulate matter was not performed using the method OECD 110 particle size distribution.

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 2006-01-11

Type of method:

sieving

Type of distribution:

volumetric distribution

Specific details on test material used for the study:

Appearance: orange, small crystals with bigger particles and powder

Remarks on result:

not measured/tested

Percentile:

D50

Remarks on result:

not measured/tested

No.:

#1

Size:

> 1 mm

Distribution:

0.6 %

No.:

#2

Size:

> 0.1 - < 1 mm

Distribution:

94.7 %

No.:

#3

Size:

< 100 µm

Distribution:

5.2 %

The complete sample (1074.45 g) was sieved manually using a 1 mm mesh sieve. Approximately 384 g of the fraction smaller then 1 mm were sieved using a sieve of 100 µm mesh. The resulting fractions were quantified gravimetrically.

Particle fraction	Initial Weight	Weight	Amount in %
Share bigger than 1 mm	1074.45 g	6.52 g	0.6 %
<1 mm but bigger than 100 µm	383.81 g	363.45	94.7 %
Particulate matter (<100 µm)		20.11	5.2 %
Total			100.5 %

A dry sieve test was performed using two sieves with a mesh size of 1 mm and 100 µm respectively. The particle size distribution was 0.6 % particles bigger than 1 mm, 94.7 % of particles <1 mm and >100 µm and 5.2 % of particulate matter (<100 µm).

At the request of the sponsor, laser diffraction was not performed because sodium (VI) dichromate is a known carcinogen and therefore a more detailed investigation of the particulate matter (<100  µm) would not reveal significantly new information relevant for risk assessment.

Conclusions:

The particle size distribution was 0.6 % particles bigger than 1 mm, 94.7 % of particles <1 mm and >100 µm and 5.2 % of particulate matter (<100 µm).

Description of key information

The particle size distribution was 0.6 % particles bigger than 1 mm, 94.7 % of particles <1 mm and >100 µm and 5.2 % of particulate matter (<100 µm).