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Guide to applying online for an assessment certificate

This guidance is designed to help you prepare and submit an online certificate application through AICIS Business Services. We also have extra guidance for chemicals at the nanoscale.

Read our ‘Apply for an assessment certificate’ page for important details about who can apply, types of certificates based on your introduction’s risk and mandatory information.


1.  Download our main guide on applying online for an assessment certificate

2.  If your chemical is at the nanoscale - you must provide extra data, see data requirements below

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Guidance on data requirements for chemicals at the nanoscale  

Nanoscale means the particle size range of 1 to 100 nm. An introduction at the nanoscale is a ‘specified class of introduction’ if it: 

  • is introduced as a solid or is in a dispersion 
  • consists of particles in an unbound state or as an aggregate or agglomerate, where at least 50% (by number size distribution) of the particles have at least one external dimension in the nanoscale 

For details, see categorisation of chemicals at the nanoscale

If your chemical is at the nanoscale and is categorised as an assessed introduction, you need to give us the following information about the chemical’s identity and physicochemical properties. 

Chemical details 

  • CAS name and/or IUPAC name 
  • CAS registry number, if available 
  • Common or trade name, if available 
  • Synonyms, if available (for example, chemical identifiers in study reports or test data reports) 
  • Molecular formula, if defined 
  • Structural formula, if defined 
  • Molecular weight or weight range, if defined 
  • Composition (for example, purity, identity of impurities, details of manufacturing method and batch-to-batch variation if applicable)  
  • Coated or not coated (if coated, the details of coating) 
  • Where relevant, information about crystallinity (crystal or amorphous structure). For example, if a chemical has different crystal structures because of the manufacturing technique; then you’ll need to provide the name/s of crystal structure/s and their proportions 

Nanoscale-specific physicochemical properties 

For nanoscale-specific physicochemical properties, multiple techniques may be needed to fully characterise a specific property. The choice of technique will depend on the individual characteristics of the chemical. When there are nano-specific methods available, you must provide justification for using a non-nano-specific method. 

The details of testing methods and important issues of risk assessment are available for nanoscale materials in the Organisation for Economic Cooperation Development’s Publications in the Series on the Safety of Manufactured Nanomaterials

Shape of the particle 

For carbon nanotubes (CNT), you also need to provide the number of walls in the CNT. 

For graphene, you also need to provide the number of plates in the particle. 

Particle size and particle size distribution (PSD)  

  • Particle size and PSD with percentages of different particle sizes in a batch. 
  • Variation between batches, if applicable. 
  • Aspect ratio (length/diameter) is required for elongated and platelet shapes. For example, carbon nanotubes to indicate whether the aspect ratio is over 3. 

For nano tubes and plates, you must provide all dimensions of the particle.  

For details of the methods to be used, see the OECD’s test guideline publication TG 125 - Nanomaterial particle size and size distribution of nanomaterials

Volume specific surface area 

For details of the methods to be used, see OECD TG 124: Determination of the volume specific surface area of manufactured nanomaterials. 

Another useful reference is ISO/TR 14187:2020: Surface chemical analysis – Characterization of nanostructured materials. 

Surface chemistry - the chemical nature of the surface of a particle 

The description must include whether the particles have been surface-treated. 

If surface treated: 

  • the chemical identity of the surface treatment agents (CAS and/or IUPAC name of the chemicals) and the amount (% w/w) applied on the particle, if applicable 
  • the chemistry imparted to the surface, for example, an agent may be used to graft new functional groups to the surface, or to oxidize/reduce existing functional groups  
  • a schematic representation of the particle surface may be provided to illustrate the surface chemistry. 

Surface charge 

You need to provide measured data on the zeta potential of the chemical. 

You may also submit isoelectric point and/or electrophoretic mobility as an indirect measurement of zeta potential. 

Measured data describing dispersibility (if relevant and information is available) 

  • The degree of dispersion refers to the relative number or mass of particles in a suspending medium and relates to the stability, aggregation and agglomeration of the chemical in relevant media (for example, water). 
  • Measured data on particle concentration. 
  • Measurement methods include (but are not limited to) light-scattering methods, single particle ICP-MS, and scanning mobility particle sizer (OECD TG 318). 

Measured data describing dustiness 

This data is only required if inhalation exposure is likely to occur. 

Measured data or suitable alternatives describing the Biological (re)activity 

This includes oxidising properties, conditions causing instability, decomposition products. 

Data on photoreactivity (if relevant) 

This requirement applies where the chemical absorbs light between 200-750 nm wavelength (UV/visible light). 

The following OECD test guidelines are available for testing the photoreactivity of chemicals (these are not specific to nanoscale chemicals or particles):  

  • OECD TG 432: In Vitro 3T3 NRU Phototoxicity Test, OECD TG 498: In vitro Phototoxicity: Reconstructed Human Epidermis Phototoxicity test method 
  • OECD TG 495: Reactive Oxygen Species (ROS) Assay for Photoreactivity. 

Human health hazards 

  • Measured data or suitable alternative data/information describing the potential human health hazards consistent with the minimum data requirements for chemical assessments and any other hazard information available to the introducer. For details, see step 4 of our ‘Guide to categorising your chemical importation or manufacture’ (Categorisation Guide). 
  • If dermal and/or inhalation exposure is expected to occur, then you must submit information on dermal and/or inhalation toxicity (acute or repeated dose). If you can’t give us this information, you must provide a justification. 

If other routes of exposure are expected, then you should provide toxicity data on those hazard end points. 

All OECD TG available for testing human health toxicity end points are considered applicable in the absence of equivalent testing guidelines for nanoscale chemicals. For details, see OECD guidelines for the testing of chemicals: health effects

Information to consider when providing toxicity data 

  1. When experimental data for the nanoscale chemical are not available or limited, you may use the read-across approach using existing data from one or more analogous nanoscale chemicals. The read-across from a nanoscale material or a bulk substance requires strong evidence and justification for their suitability to the assessed chemical. You can follow grouping of chemicals when assessing the validity of an analogue. For details, see working out your hazards using read-across information
  2. Information on genetic toxicity – the Ames test (OECD TG 471) is not considered to be a reliable test to confirm negative results for mutagenicity of nanoscale particles.  
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