N-(2,3-dihydro-2-oxo-1H-benzimidazol-5-yl)-3-hydroxy-4-[[2-methoxy-5-methyl-4-[(methylamino)sulphonyl]phenyl]azo]naphthalene-2-carboxamide

Nanomaterial dustiness

Administrative data

Endpoint:

nanomaterial dustiness

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15-09-2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: DIN EN 17199-3

Version / remarks:

Workplace exposure - Measurement of dustiness of bulk materials that contain or release respirable NOAA or other respirable particles - Part 3: Continuous drop method

Deviations:

yes

Remarks:

test conditions (humidity) due to laboratory environment; 1 meaurement performed

GLP compliance:

no

Type of method:

continuous drop

Details on methods and data evaluation:

In the continuous drop method, the bulk material falls continuously into a slight vertical counter air flow. The dust released by the falling bulk material is directed by the air stream (53 l/min) into a sampling section where direct reading aerosol measuring devices (SMPS/OPS) measure the time-resolved particle concentrations and the time-resolved particle size distribution of the aerosol.
The number size distribution of particles between 10 and 417 nm is determined using a TSI SMPS (model 3910) equipped with isopropanol based CPC (condensation particle counter). The number size distribution of particles between 0.3 and 10 μm is determined using a TSI OPS (model 3330) integrated in the SMPS.
A special downpipe was used for the detection of possibly released product nanoparticles (including submicron agglomerates) according to the above mentioned method and following the standard DIN EN 15051-3 "Workplace exposure -Measurement of the dustiness of bulk materials - Part 3: Continuous drop method.
In the downpipe described above, the counterflow is provided by cleaned, almost particle-free air (upstream ULPA filter type U15), so that possible background pollution in the room air is eliminated and measured nanoparticles can be clearly assigned to the product.

Sampling:

The test material was used without further treatment (e.g. drying). 57.5 g (287.5 cm3) test material are used for the measurement, dosing rate: 5.75 g/min.

Test material

Test material information

Constituent 1

Reference substance name:

N-(2,3-dihydro-2-oxo-1H-benzimidazol-5-yl)-3-hydroxy-4-[[2-methoxy-5-methyl-4-[(methylamino)sulphonyl]phenyl]azo]naphthalene-2-carboxamide

EC Number:

257-515-0

EC Name:

N-(2,3-dihydro-2-oxo-1H-benzimidazol-5-yl)-3-hydroxy-4-[[2-methoxy-5-methyl-4-[(methylamino)sulphonyl]phenyl]azo]naphthalene-2-carboxamide

Cas Number:

51920-12-8

Molecular formula:

C27H24N6O6S

IUPAC Name:

3-hydroxy-4-{[2-methoxy-5-methyl-4-(methylsulfamoyl)phenyl]diazenyl}-N-(2-oxo-2,3-dihydro-1H-benzimidazol-5-yl)-2-naphthamide

Test material form:

solid: nanoform, no surface treatment

Results and discussion

Dustiness index

Dustiness index 1

Key result

Mean:

27 989 862.6 other: 1/mg

Remarks on result:

other: dustiness index as number of airborne particles per mg in the nanoscale (10 nm - 100 nm)

Dustiness index 2

Mean:

3 036.6 other: N/cm3

Remarks on result:

other: number of airborne nanoparticles per cm3

Any other information on results incl. tables

temperature: 24°C, rel. air humidity 63 %

The cleaned, almost particle-free air had a total particle count of 17 particles/cm3 in the range of 10 nm - 417 nm, the nanoscale fraction (10 - 100 nm) contained 12 particles/cm3.

Table 1: summary SMPS (scanning mobility particle sizer)

Range [nm]	Mean [nm]	Concentration [N/cm3]	ICD[1/mg]	ECD[1/mg·s]
10-100	75.8	3036.6	27989862.6	46649.8
100-417	169.8	13922.1	128325659	213876,1
10-417	153	16958,8	156315521,6	260525,9

ICD: dustiness index as number of airborne particles per mg

ECD: emission rate as number of particles per mg per second

mean: average particle diameter in nm
N: number of airborne particles

Table 2: summary OPS (optical particle sizer)

Range [μm]	Mean [μm]	Concentration [N/cm3]	ICD[1/mg]	ECD[1/mg·s]
0.3 - 10	4.3	33.2	305601.1	509.3

Applicant's summary and conclusion

Executive summary:

The dusting behaviour of the test material was investigated using DIN EN 17199 -3: 2019 -12 "workplace exposure - measurement of dustiness of bulk materials that contain or release respirable nano objects and their aggregates and agglomerates or other respirable particles- Part 3: Copntinuous drop method".

The dust released by the falling test material was measured by a scanning mobility particle sizer (SMPS, 10 - 417 nm) and an optical particle sizer (3 - 10 μm). The counterflow was provided by cleaned, almost particle-free air.

The SMPS counted 3036.6 particles per cm3 in the nanoscale (10 - 100 m) (13922.1 particles per cm3 in the range of particles 10 -417 nm) corresponding to a dustiness index of 27989862.6 particles per mg in the nanoscale (10 - 100 nm) (388870.1 particles per mg in the range of [articles 10 -417 nm).

The mean size of the nanoparticles was 75.8 nm, the mean size of particles in the range 10 - 417 nm was 153.

The OPS (0.3 - 10 μm) counted 33.2 particles per cm3 corresponding to a dustiness index of 305601.1 particles per mg. The mean size of the particles was 4.3 μm.