A
Chemical Abstracts Service (CAS) Number is a unique numerical identifier assigned to every chemical substance described in the open scientific literature. This includes organic and inorganic compounds, minerals, isotopes, alloys, and nonstructurable materials. The CAS number is a key tool for precise and unambiguous identification of substances in the realm of
chemical research and industry.
Importance of CAS Numbers in Nanotechnology
In
Nanotechnology, the CAS number is crucial for identifying and categorizing various
nanomaterials and
nanoparticles. Given the complexity and diversity of substances at the nanoscale, having a standardized identifier aids in:
1. Research and Development: Facilitating the search for specific nanoparticles and other nanomaterials in databases and scientific literature.
2. Regulatory Compliance: Ensuring that nanomaterials meet safety and environmental regulations.
3. Commercialization: Helping companies identify and procure the correct nanomaterials for their products.
The CAS number is assigned by the Chemical Abstracts Service, a division of the
American Chemical Society. Each substance is given a unique number in a sequence format (e.g., 58-08-2). The assignment involves a thorough review of the substance's chemical structure and properties to ensure accuracy and uniqueness.
Examples of CAS Numbers in Nanotechnology
Different nanomaterials have distinct CAS numbers. For example:
- Carbon Nanotubes: Single-walled carbon nanotubes (SWCNTs) have the CAS number 308068-56-6.
- Gold Nanoparticles: Gold nanoparticles have the CAS number 7440-57-5.
- Silica Nanoparticles: Silica nanoparticles are identified with the CAS number 7631-86-9.
These identifiers are pivotal for researchers to locate relevant safety data sheets (SDS), toxicity studies, and other critical information.
Challenges and Limitations
Despite its advantages, the CAS number system has limitations in the context of nanotechnology:
1. Complexity of Nano Structures: Nanomaterials often have complex, multi-component structures that may not be fully captured by a single CAS number.
2. Dynamic Properties: The physical and chemical properties of nanomaterials can change with size, shape, and surface modifications, making a single CAS number insufficient for comprehensive identification.
3. Emerging Materials: The rapid development of new nanomaterials often outpaces the assignment of CAS numbers, leading to temporary gaps in identification.
Future Directions
To address these challenges, the Chemical Abstracts Service and other stakeholders are working on:
1.
Enhanced Databases: Developing more comprehensive databases that include detailed descriptions of nanomaterial properties and modifications.
2.
Integrated Systems: Combining CAS numbers with other identification systems, such as
InChI (International Chemical Identifier), to provide more detailed and dynamic information.
3.
Global Collaboration: Promoting international collaboration to standardize nanomaterial identification and regulatory practices.
Conclusion
The CAS number is an indispensable tool in nanotechnology, providing a standardized and reliable way to identify and categorize nanomaterials. While challenges remain, ongoing advancements in database integration and international collaboration promise to enhance the utility and accuracy of CAS numbers in the ever-evolving field of nanotechnology.
