Phosphoric acid, hexadecyl phosphate esters, potassium salts with cetostearyl alcohol

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:

From July 20, 2017 to September 21, 2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Qualifier:

equivalent or similar to guideline

Guideline:

other: ISO 2591-1

Version / remarks:

ISO 2591-1:1988, Test sieving -- Part 1: Methods using test sieves of woven wire cloth and perforated metal plate

Deviations:

not specified

Principles of method if other than guideline:

To characterise the particle size distribution of the test substance, the analysis was conducted initially using an optical microscope analysis and was then undertaken more formally using a manual sieve analysis.

GLP compliance:

yes

Type of method:

other: Sieving and microscopic examination

Type of particle tested:

other: As received, the test substance is observed to be white granules

Type of distribution:

mass based distribution

No.:

#1

Size:

> 2 000 µm

Distribution:

ca. 100 %

No.:

#2

Size:

< 2 000 µm

Distribution:

ca. 0.04 %

Remarks on result:

other: Only 0.04 % of the test substance was found to be < 2 mm in particle size. Consequently the distribution analysis was not performed.

Results 

1) Optical microscope analysis

Standard visual observation

Test substance was observed to be coarse to fine, amorphous, free flowing white granules.

Observation using 3.2 objective lens

The particles appeared to be irregular shaped crystals.

Observation using 40 objective lens

The test substance was observed to be made up of single particles.

2) Manual sieve analysis

Full test results

Sieve size (μm)	Sieve weight (g)	Sieve + powder weight (g)	Powder weight (g)		% by weight
> 2000	352.84	903.37	550.5		100.0
< 2000	356.4	356.62	0.2		0.04
Total				550.8	100.0

Only 0.04 % of the test substance was found to be < 2 mm in particle size. Consequently the distribution analysis was not performed.

Conclusions:

Under the study conditions, the particle size of the test substance was considered to be >2000 µm.

Executive summary:

A study was conducted to determine the particle size distribution of the test substance, using an optical microscopic and manual sieve analysis. The test susbtance as received was observed to be coarse to fine, amorphous, free flowing white granules. During sieve analysis, only 0.04% of the test substance passed through the 2000 µm sieve. Because test substance particles were greater than the upper limit of detection for the distribution analysis, the author concluded that no further testing was required. Under the study conditions, the particle size of the test substance was considered to be >2000 µm (Chilworth, 2017).

Description of key information

The particle size distribution of the test substance was determined using optical microscopicy and manual sieve analysis method (Chilworth, 2017).

Additional information

Value used for CSA: >2000 µm

(for ca. 100% of the test substance; only 0.04%<2000 µm)