ASTM D7772-15(2023)

Standard Test Method for Carbon Black Extractables – Absorbance of Cyclohexane Extract

SIGNIFICANCE AND USE
4.1 This procedure serves as a screening process for carbon blacks used in the manufacturing of products that are to come into contact with food. The cyclohexane extract absorbance at 386 nm must be less than 0.10 for a 50 mm cuvette in order to fulfill various regulatory requirements.
SCOPE
1.1 This method covers the determination of extinction (absorbance) of carbon black cyclohexane extract at 386 nm using a UV spectrophotometer.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Oct-2023
• ICS: 83.040.20 - Rubber compounding ingredients
• Technical Committee: D24 - Carbon Black
• Drafting Committee: D24.66 - Environment, Health, and Safety

Relations

• Replaces: ASTM D7772-15(2019) - Standard Test Method for Carbon Black Extractables – Absorbance of Cyclohexane Extract
• Effective Date: 01-Nov-2023

Overview

ASTM D7772-15(2023), "Standard Test Method for Carbon Black Extractables – Absorbance of Cyclohexane Extract," is a critical standard developed by ASTM International. This test method provides a reliable procedure for determining the absorbance (extinction) of cyclohexane extracts from carbon black using a UV spectrophotometer. It is particularly significant for ensuring the safety of carbon black used in products that may come into contact with food. The test helps manufacturers confirm compliance with regulatory requirements that protect public health and consumer safety, especially regarding potential extractables from carbon black.

Key Topics

• Purpose: Screen carbon black for extractables that could migrate into food-contact materials.
• Test Principle: Measures the absorbance of cyclohexane-soluble components in carbon black at 386 nm using a UV spectrophotometer.
• Regulatory Compliance: Absorbance must be less than 0.10 for a 50 mm cuvette to fulfill various regulatory requirements.
• Precision and Reproducibility: The method provides robust repeatability (r = 0.013 absorbance units) and reproducibility (R = 0.024 absorbance units), supporting consistent results across laboratories.
• Safety Considerations: The procedure involves cyclohexane, a solvent requiring strict adherence to health and safety protocols, such as using gloves and working within a fume hood.
• Laboratory Requirements: Involves use of calibrated spectrophotometers, specific cuvettes, filtration equipment, and analytical balances.

Applications

ASTM D7772-15(2023) is widely applied in:

• Quality Control in Carbon Black Production: Used by manufacturers to certify materials intended for food contact applications, such as plastics, coatings, and packaging.
• Compliance Testing: Ensures adherence to regulatory limits for extractables as required by food safety laws and directives.
• Research and Development: Applied by laboratories and research institutions in developing new grades of carbon black or evaluating existing products for migration potential.
• Third-Party Testing Services: Utilized by independent labs offering compliance and certification services for food-contact plastics and carbon black suppliers.

Related Standards

When implementing ASTM D7772-15(2023), consider the following related standards and references to support compliance and best practices:

• ASTM D4483: Practice for Evaluating Precision for Test Method Standards in the Rubber and Carbon Black Manufacturing Industries.
• German Federal Communications: Specifications on the purity testing of carbon black in plastics (various publications).
• International Regulations: Standards and guidance from the World Trade Organization Technical Barriers to Trade (TBT) Committee, ensuring harmonization and global acceptance.
• Other ASTM Standards: Refer to the ASTM website for updates and complementary testing methods relevant to carbon black and food-contact materials.

Practical Value

Utilizing ASTM D7772-15(2023) in quality assurance processes offers:

• Verified Food Safety: Demonstrates that carbon black products meet stringent extractable limits for food-contact safety.
• Market Access: Satisfies requirements for regulatory approval and facilitates trade of carbon black-containing materials globally.
• Risk Management: Minimizes liability and reputational risks associated with non-compliance to food safety standards.
• Consistent Quality: Standardized testing supports uniformity and trust in supply chains serving the food packaging and processing industries.

Keywords: ASTM D7772-15, carbon black, cyclohexane extract, absorbance, UV spectrophotometer, food contact materials, regulatory compliance, extractables testing, food safety standard.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D7772 − 15 (Reapproved 2023)
Standard Test Method for
Carbon Black Extractables – Absorbance of Cyclohexane
Extract
This standard is issued under the fixed designation D7772; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Significance and Use
1.1 This method covers the determination of extinction
4.1 This procedure serves as a screening process for carbon
(absorbance) of carbon black cyclohexane extract at 386 nm
blacks used in the manufacturing of products that are to come
using a UV spectrophotometer.
into contact with food. The cyclohexane extract absorbance at
386 nm must be less than 0.10 for a 50 mm cuvette in order to
1.2 The values stated in SI units are to be regarded as
fulfill various regulatory requirements.
standard. No other units of measurement are included in this
standard.
5. Apparatus
1.3 This standard does not purport to address all of the
5.1 Spectrophotometer, 20 nm maximum spectral bandpass,
safety concerns, if any, associated with its use. It is the
capable of measuring absorbance at 386 nm.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
5.2 Cuvettes, with an optical light path of 50 mm.
mine the applicability of regulatory limitations prior to use.
5.3 Balance, analytical, sensitivity 0.01 g.
1.4 This international standard was developed in accor-
dance with internationally recognized principles on standard-
5.4 Filter Paper, with a particle retention in liquid less than
ization established in the Decision on Principles for the
2 μm.
Development of International Standards, Guides and Recom-
5.5 Glass Filtering Funnels, 75 mm diameter at top.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. 5.6 Volumetric Flask, 100 cm .
5.7 Lens Cleaning Tissue, lint free.
2. Referenced Documents
2 5.8 Timer, with 1 s divisions.
2.1 ASTM Standards:
D4483 Practice for Evaluating Precision for Test Method 5.9 Oven, gravity-convection type, capable of temperature
Standards in the Rubber and Carbon Black Manufacturing
regulation of 125 °C 6 5 °C.
Industries
5.10 Desiccator.
3. Summary of Test Method
5.11 As a good laboratory practice, it could be suggested the
use of a Neutral Density Filter with a spectral absorbance
3.1 A carbon black sample is gently agitated in cyclohexane
calibrated at 386 nm to ensure the spectrophotometer is
at room temperature to remove any extractable material. The
correctly calibrated.
mixture is left standing in the dark for 24 h at room tempera-
ture. The carbon black is separated from the cyclohexane by
6. Reagents and Materials
filtration, with subsequent determination of the extinction of
the filtrate at 386 nm using a 50-mm cuvette.
6.1 Cyclohexane, analytical reagent grade.
7. Hazards
This test method is under the jurisdiction of ASTM Committee D24 on Carbon
Black and is the direct responsibility of Subcommittee D24.66 on Environment,
7.1 This test involves hazardous materials, operations and
Health, and Safety.
equipment. This procedure does not attempt to address the
Current edition approved Nov. 1, 2023. Published December 2023. Originally
safety problems associated with this test. A hazards review
approved in 2011. Last previous edition approved in 2019 as D7772 – 15 (2019).
DOI: 10.1520/D7772-15R23.
must be conducted by all personnel performing the test. It is the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
responsibility of the user to review all MSDS, manuals and
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
hazards procedures and establish the appropriate safety mea-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. sures.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7772 − 15 (2023)
TABLE 1 Precision Parameters for Test Method D7772, Carbon Black Extractables-Absorbance of Cyclohexane Extract (Type 1 Preci-
sion)
Number of Unit Absor-
Material Sr r (r) SR R (R)
Labs bance
N772 4 0.008 0.005 0.015 203.78 0.007 0.020 269.58
N683 (SRB
4 0.011 0.004 0.011 101.72 0.009 0.026 249.15
8F)
Average 0.009
Pooled 0.005 0.013 146.05 0.008 0.024 259.90
8. Calibration, Standardization, and Environmental 9.3 Weigh 1.00 g 6 0.01 g sample and transfer to a 100 cm
Conditions volumetric flask.
8.1 Standard Laboratory Test Conditions: 9.4 It is imperative that steps 9.5 – 9.9 are carried out in a
8.1.1 Unless stated elsewhere, all testing, calibration and fume hood using disposable nitrile gloves. This kind of gloves
standardization should be carried out in the ambient tempera- are recommended for cyclohexane to prevent skin exposure
ture range of 23 °C 6 3 °C. (cyclohexane can cause skin irritation).
8.1.2 The date of calibration or testing should also be 3 3
9.5 Add 25 cm to 30 cm of cyclohexane to the sample
recorded with any relevant data.
flask and stopper the flask.
8.1.3 All calibration data should be recorded on a dedicated
9.6 Shake the mixture gently for a few seconds.
file.
9.7 Fill up to the mark with cyclohexane.
8.2 Instrument Set-Up Frequency – Day of Test:
8.2.1 Turn on the spectrophotometer and allow it to warm 9.8 Close the flask with a stopper, gently shake the mixture
up for 30 min. again for a few seconds and place it in dark for 24 h at room
8.2.2 Set the wavelength to 386 nm and zero the instrument.
temperature.
8.2.3 Place the Neutral Density Filter inside the sample
9.9 After 24 h, filter the mixture through the filter paper and
compartment of the instrument and verify the absorbance value
collect the filtrate in a graduated cylinder. As soon as the
is within the absorbance tolerance. If the filter is found to be
filtration is complete, stopper the graduated cylinder until
outside the limits, verify the filter’s absorbance using a more
ready to test.
sophisticated UV/Vis Spectrometer. If in this case nothing
9.10 Using the same cuvette as described in 8.2.6, rinse and
abnormal is found for the filter, service and calibrate the
fill the cuvette with sample filtrate.
spectrophotometer.
9.10.1 The same cuvette must be used for the blank and all
8.2.4 It is imperative that steps 8.2.5 – 8.2.8 are carried out
samples, as differences in the optical density of different
in a fume hood using disposable nitrile gloves. This kind of
cuvettes will cause errors.
gloves are recommended for cyclohexane to prevent skin
exposure (cyclohexane can cause skin irritation).
9.11 Insert the cuvette into the spectrophotometer and
8.2.5 Filter approximately 50 cm cycloh
...