Zinc oxide

Nanomaterial specific surface area

Administrative data

Endpoint:

nanomaterial specific surface area

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study was regarded as scientifically acceptable. However, only limited documentation of the data evaluation was provided in the full study report. Furthermore the procedure for subsampling and data analysis and representation was not explained in detail. There are specific sample splitting practices to be followed (cf. ISO 14488:2007). It was not indicated in the study report that these sampling procedures were followed. Thus, there is a doubt that the sample could be considered to be representative of the whole sample with a defined confidence level. Thus, it was not possible to assess the validity of the provided data as the sample preparation and the data analysis could have a significant influence to the result. The most requirements as outlined in ECHA guidance were fulfilled. Thus, the results were regarded as reliable with restrictions.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

ISO 9277 Determination of the specific surface area of solids by gas adsorption - BET method

Version / remarks:

2010

Deviations:

not specified

Principles of method if other than guideline:

BET surface area measurements were determined using Autosorb-1 (Quantachrome Instruments). The Autosorb-1 was calibrated using a quartz rod of a known volume, which is traceable to NIST. This calibration was then further checked using two BAM certified reference materials: BAM-PM-102 (nominal SSA 5.41m2g-1) and BAM-PM-104 (nominal SSA 79.8 m2g-1). These two reference materials allowed the range of SSA of the nanoparticles to be encompassed with known specific surface area materials, thus adding confidence to the measurements. Surface area measurements were acquired using an 11-point BET gas adsorption method, with nitrogen as the adsorbate. Prior to analysis, the powdered sample was transferred to a sample bulb, then sealed and subsequently de-gassed overnight at 300 °C under a high vacuum and subsequently weighed on an analytical balance in order to determine the sample mass after the degassing step.

GLP compliance:

no

Type of method:

BET

Remarks:

BET (Brunauer, Emmett and Teller) Multipoint Specific Surface Area determination

Details on methods and data evaluation:

Each sample was degassed overnight at 300°C and under vacuum. An 11-point BET measurement using nitrogen was then taken. This measurement was carried out on two separate aliquots of each powder.

Test material

Test material information

Constituent 1

Reference substance name:

Zinc oxide

EC Number:

215-222-5

EC Name:

Zinc oxide

Cas Number:

1314-13-2

Molecular formula:

ZnO

IUPAC Name:

oxozinc

Test material form:

solid: nanoform

Specific details on test material used for the study:

Name of test material: Z-cote ®
Code: NM110
Supplier: BASF SE
Surface coating: none
- Substance type: Inorganic
- Physical state: solid powder, nano-form

-Name of test material: Z-cote HP
Code: NM111
Supplier: BASF SE
Surface coating: triethoxycaprylylsilane (2%)
- Substance type: Inorganic
- Physical state: solid powder, nano-form

-Name of test material: NanosunTM
Code: NM112
Supplier: Micronisers
Surface coating: none
- Substance type: Inorganic
- Physical state: solid powder, nano-form

-Name of test material: Zinc Oxide
Code: NM113
Supplier: Sigma-Aldrich
Surface coating: none
- Substance type: Inorganic
- Physical state: solid powder, nano-form

Reference material / nanomaterial and sample identification number

Reference

Reference substance name:

Unnamed

Data gathering

Instruments:

Autosorb-AS1

Calibration:

Manifold calibration using a calibrated quartz rod
SSA calibration carried out using BAM CRM BAM-PM-102 and BAM CRM BAM-PM-104

Results and discussion

Specific surface area

Specific surface area 1

Specific Surface Area:

12.4 m²/g

Remarks on result:

other: NM-110

Specific surface area 2

Specific Surface Area:

m²/g

Remarks on result:

other: NM-111

Specific surface area 3

Specific Surface Area:

27.2 m²/g

Remarks on result:

other: NM-112

Specific surface area 4

Specific Surface Area:

6.2 m²/g

Remarks on result:

other: NM-113

Applicant's summary and conclusion

Conclusions:

The specific surface area was determined to be 12.4 ± 0.6 m2/g for NM-110, 15.1 ± 0.6 m2/g for NM-11, 27.92 ± 1.2 m2/g for NM-112 and 6.2 ± 0.3 m2/g for NM-113.

Executive summary:

 The specific surface area of the NMs was investigated NPL, 2010 using BET Multipoint Specific Surface Area (SSA) determination. BET surface area measurements were determined using Autosorb-1 (Quantachrome Instruments). The Autosorb-1 was calibrated using a quartz rod of a known volume, which is traceable to NIST. This calibration was then further checked using two BAM certified reference materials: BAM-PM-102 (nominal SSA 5.41 m2/g) and BAM-PM-104 (nominal SSA 79.8 m²/g). These two reference materials allowed the range of SSA of the nanoparticles to be encompassed with known specific surface area materials, thus adding confidence to the measurements. Surface area measurements were acquired using an 11-point BET gas adsorption method, with nitrogen as the adsorbate. Prior to analysis, the powdered sample was transferred to a sample bulb, then sealed and subsequently de-gassed overnight at 300 °C under a high vacuum and subsequently weighed on an analytical balance in order to determine the sample mass after the degassing step. The specific surface area was determined to be 12.4 ± 0.6 m2/g for NM-110, 15.1 ± 0.6 m2/g for NM-11, 27.92 ± 1.2 m2/g for NM-112 and 6.2 ± 0.3 m2/g for NM-113.