branched and cross-linked multi-walled carbon nanotubes

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:

2021

Report date:

2021

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: DIN 55992-1:2006 ("Determination of a parameter for the dust formation of pigments and extenders - Part 1: Rotation method").

Deviations:

no

GLP compliance:

no

Type of method:

rotating cylinder

Test material

Test material information

Constituent 1

Reference substance name:

branched and cross-linked multi-walled carbon nanotubes

Molecular formula:

C

IUPAC Name:

branched and cross-linked multi-walled carbon nanotubes

Test material form:

solid: nanoform, no surface treatment

Specific details on test material used for the study:

Product name: ATHLOS 200 CARBON NANOSTRUCTURE PELLETS
Batch-No.: V20169
Substance name: Carbon
Chemical formula: C
Appearance: Black odourless pelltes
Physical state: Solid
Substance density: 2 g/cm³
Substance humidity: 0.08 % (by DMT)
Substance stability: Stable under normal conditions

Results and discussion

Dustiness index

Key result

Mean:

ca. 15.52 other: mg/g

St. dev.:

0 other: mg/g

Any other information on results incl. tables

Summary of results of the examined dust sample

Quantity of substance used	1.00 g	Relative amounts of used quantity	Relative amounts of the whole fraction
Total dust mass in impactor	15.53 mg
Mass Median Aerodynamic Diameter (MMAD)*	20.50 µm
Geometric Standard Deviation (GSD)*	3.80 µm
Total dustiness, whole fraction	15.52 mg/g
Dustiness, inhalable fraction	10.97 mg/g	1.10%	70.69%
Dustiness, thoracic fraction	6.29 mg/g	0.63%	40.55%
Dustiness, alveolar fraction	3.73 mg/g	0.37%	24.04%

*Median of the distribution of airborne particle mass with respect to the aerodynamic diameter. MMAD is one of the metrics most widely adopted as a single number descriptor of aerodynamic particle-size distribution. MMADs are usually accompanied by the geometric standard deviation (GSD) which characterizes the variability of the particle size distribution. The diameter that divides the mass distribution of an aerosol in half [P.A. Baron, K. Willecke; Aerosol Measurement, 2005].

Applicant's summary and conclusion

Conclusions:

The most important result of this examination is, that for ATHLOS 200 CARBON
NANOSTRUCTURE PELLETS, the respirable fraction represented 0.37 % of the quantity of
the substance used under the modified Heubach procedure

Executive summary:

Examinations were performed to determine the dustiness of a substance sample designated as "ATHLOS 200 CARBON NANOSTRUCTURE PELLETS". The objective of these examinations was to determine the dust fractions of this substance. These are the dust fractions which are defined in DIN EN 481 as the:
Inhalable fraction
Thoracic fraction
Respirable fraction
The modified Heubach procedure was applied. In the process, the substance sample was mechanically stressed in a rotating drum (dust generation device), and both the dust already contained in this sample and the dust generated due to abrasion were removed from the dust generation device by an air current. The proportion of dust separated and considered as dust with the ability to become airborne was fed into a seven-stage cascade impactor connected to the dust generation device. Particle size classification was conducted by subsequent weighing of the respective dust masses deposited on the individual cascade stages reflecting certain particle size ranges.
The “total dustiness” value was determined as the ratio of the mass of removed dust to the total sample mass initially weighed in.
Subsequently, the dustiness values for the inhalable, thoracic and respirable fractions according to DIN EN 481 were determined

Dustiness values of the "ATHLOS 200 CARBON NANOSTRUCTURE PELLETS" sample

Total dustiness [mg/g]	15.52
Inhalable fraction [mg/g]	10.97 (1.10 %)
Thoracic fraction [mg/g]	6.29 (0.63 %)
Respirable fraction [mg/g]	3.73 (0.37 %)
Mass Median Aerodynamic Diameter (MMAD) [μm]	20.5
Geometric Standard Deviation (GSD) [μm]	3.8

As a conclusion, for the sample “ATHLOS 200 CARBON NANOSTRUCTURE PELLETS”, the respirable fraction represented 0.37 % of the quantity of the substance used under the Modified Heubach procedure.