2,2'-[(2,2',5,5'-tetrachloro[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[N-(2,4-dimethylphenyl)-3-oxobutyramide]

Nanomaterial dustiness

Administrative data

Endpoint:

nanomaterial dustiness

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2022

Report date:

2022

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EN 15051-2 (Workplace exposure. Measurement of the dustiness of bulk materials - Rotating drum method)

GLP compliance:

not specified

Type of method:

rotating cylinder

Details on methods and data evaluation:

The sample has been divided in eight equal lots of about 35 ml using a rotary riffler, this rotary riffler is especially designed to minimize the loss of any fine dust. One of these divided lots has been used for determining the bulk density and the moisture content as well. The bulk density of the sample has been determined by accurately weighing a volume of 100 cm3 after gentle tapping at the side. This bulk density is used to convert the sample mass to the required volume of approx. 35 cm3 and the sample is further divided to the required 35 cm3. A few grams of each sample have been placed in the moisture analyser and have been heated to 105°C until a stable mass has been reached. The relative mass loss so-obtained has been quantified as moisture content as an independent triplicate.

One of the divided sub lots of about 35 cm3 is accurately weighed and placed in the rotating drum and the airborne dust particles are transferred by an air flow rate of 38 l min-1 to the filter assembly during 1 minute. The airborne dust released is drawn from the dust generation section, through the dust transfer section, into the special designed foam/filter assembly with successively 20 pores per inch foam, 80 pores per inch foam and a glass fibre backing filter. The complete procedure is repeated several times with fresh sample material and clean filters, each dustiness measurement is preceded by a blank run. Dustiness is a relative term and the result obtained will depend on the used test apparatus, the properties of the material and various environmental variables.

Sampling:

The dust sampling system of the EN 15051-2 Rotating Drum method is constructed in such a way that the largest airborne particles are collected on a foam filter with 20 pores per inch foam. Smaller airborne particles pass through this filter and are collected on a second foam filter with 80 pores per inch foam. Only the smallest airborne particles pass through both foam filters and are collected on a glass fibre backing filter. The dust collected on the glass fibre backing filter is presented as the respirable fraction.
In accordance with the respirable convention described in ISO 7708 the adult respirable fraction shown in Figure 1 is given by a cumulative log-normal distribution with a median diameter of 4.25 μm and a geometric standard deviation of 1.5.2 This results that 100% of the particles with an aerodynamic diameter < 16 μm are classified as respirable and it is assumed that these particles are all collected on the glass fibre backing filter.
According to the respirable convention, 98.7% of the particles collected by the EN 15051 methodology on this glass fibre backing filter then have an aerodynamic particle diameter ≤ 10 μm.

Test material

Test material information

Constituent 1

Reference substance name:

2,2'-[(2,2',5,5'-tetrachloro[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[N-(2,4-dimethylphenyl)-3-oxobutyramide]

EC Number:

244-776-0

EC Name:

2,2'-[(2,2',5,5'-tetrachloro[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[N-(2,4-dimethylphenyl)-3-oxobutyramide]

Cas Number:

22094-93-5

Molecular formula:

C36H32Cl4N6O4

IUPAC Name:

2,2'-[(2,2',5,5'-tetrachlorobiphenyl-4,4'-diyl)didiazene-2,1-diyl]bis[N-(2,4-dimethylphenyl)-3-oxobutanamide]

Test material form:

solid: nanoform, no surface treatment

Data gathering

Instruments:

15051 rotating drum dustiness tester

Reproducibility:

The average relative standard deviation (RSD) of the intra RSD is typically below 17%. The relative standard deviations obtained for the independent measurements are all below 8 % and are thus well within the range of RSD values typically found for this methodology, confirming adequate sampling.

Results and discussion

Dustiness index

Dustiness index 1

Mean:

ca. 7 676 mg/kg

St. dev.:

4.8 other: %

Remarks on result:

other: inhalable fraction

Dustiness index 2

Mean:

ca. 944 mg/kg

St. dev.:

4.2 other: %

Remarks on result:

other: thoracic fraction

Dustiness index 3

Mean:

ca. 88 mg/kg

St. dev.:

3.9 other: %

Remarks on result:

other: respirable fraction

Any other information on results incl. tables

Category of dustiness	Inhalable dustiness mass fraction, mg kg-1	Thoracic dustiness mass fraction, mg kg-1	Respirable dustiness mass fraction, mg kg-1
very low	<300	<80	<10
Low	300-650	80-300	10-60
Moderate	650-3000	300-1000	60-210
High	>3000	>1000	>210

Inhalable fraction: high classification

thoracic fraction: moderate classification

respirable fraction: moderate classification

Applicant's summary and conclusion

Conclusions:

The substance was tested for dustiness for nanomaterials, following EN15051-2 rotating drum equipment. Under the experimental conditions the test item has the following results, ca. 7676 mg kg-1 for the inhalable fraction (high classification), 944 mg kg-1 for the thoracic fraction (moderate classification) and 88 mg kg-1 for the respirable fraction (moderate classification)

Executive summary:

The substance was tested for dustiness for nanomaterials, following EN15051-2 rotating drum equipment. Under the experimental conditions the test item has the following results, ca. 7676 mg kg-1 for the inhalable fraction (high classification), 944 mg kg-1 for the thoracic fraction (moderate classification) and 88 mg kg-1 for the respirable fraction (moderate classification)