Nanomaterials

Risks and characteristics of nanomaterials

• Size and behavior. Airborne persistence, respiratory deposition and movement to other tissues depend on material characteristics and exposure; they are not identical for every nanoparticle.
• Reactivity and surface area. Surface characteristics and modification can influence reactivity and toxicity. Mass may need complementary information about size, number, composition or morphology; it should not be dismissed where relevant to the method or criterion used.
• Shape and solubility. Long, biopersistent fibers (some carbon nanotubes) and insoluble materials raise greater concerns; aggregation and coating modify behavior.
• Toxicological uncertainty. Information is incomplete for many nanomaterials, and safety data sheets do not always describe nanoforms, requiring the application of the precautionary principle.
• Absence of specific limit values. There are no occupational exposure limits for most nanomaterials, and measurements require special instrumentation and strategies (particle number, surface area, microscopy).
• Safety risks. Some metallic and carbon nanopowders present a higher risk of fire and explosion, and nanoparticles can act as catalysts.

Applicable regulatory framework

Spanish Law 31/1995 and Royal Decree 374/2001 require identification of hazards and assessment of exposure and working conditions, including maintenance and foreseeable incidents, with measures following the preventive hierarchy. Royal Decree 665/1997 applies where its criteria are met: substances or mixtures meeting the classification criteria for Category 1A or 1B carcinogenicity, germ-cell mutagenicity or reproductive toxicity, and the cases covered by its Annex I. Check the material and form actually used. A scientific classification or membership of the nanotube family does not automatically trigger that regime. Where applicable, substitution is required when technically possible, followed by a closed system, where technically possible, if substitution is not possible, together with the other measures and conditions in Articles 4 and 5, including distinctions for reprotoxic agents.

Within the European Union, the REACH Regulation, since January 1, 2020, following the amendment of its annexes by Regulation (EU) 2018/1881, requires registrants to characterize the nanoforms of substances and provide specific information on their properties and hazards, thus progressively improving the content of safety data sheets. The 2022 Commission Recommendation updates the definition of nanomaterial for use in legislation, and the CLP Regulation governs classification and labelling. The INSST (National Institute for Safety and Health at Work) offers NTP 1172 on preventive measures, NTP 877 on risk assessment using simplified methodologies (control banding), and a thematic portal with documentation and frequently asked questions.

Recommended preventive measures

• Planning. Consult the safety data sheets and supplier information on nanoforms, specific procedures for each task, and delimited work areas, if possible under negative pressure.
• Avoid dispersion. Preference for liquid suspensions over powders, closed systems, minimal transfer distances, and avoid aerosolization.
• Technical controls. Localized extraction with booths and cabinets, high-efficiency filtration (HEPA) in the extracted air and in the cleaning, and adequate general ventilation.
• Organizational measures. Reduction of the number of people and exposure time, restricted access, registration of exposures and signage.
• Personal protection. Selection follows the assessment of each task and the contaminants present: suitable respiratory protection, compatible gloves, eye protection and protective clothing where necessary, with fit checks and donning and doffing procedures. Particle filters alone do not protect against gases, vapours or oxygen deficiency.
• Cleaning and waste. Methods that prevent dispersion, using compatible wet cleaning or suitable vacuuming and effective filtration; avoid dry sweeping and compressed air. Handle waste cautiously and document its classification and management under applicable rules.
• Health surveillance. Surveillance proportionate to specific risks and personal circumstances, with justified examinations, exposure information and confidentiality; not an identical package for every nanomaterial.

Organizational application: how to manage nanomaterials

1. Inventory the nanomaterials present (raw materials, intermediate products, waste), collect information from suppliers and safety data sheets on nanoforms, and classify the processes by release potential.
2. Assess each task using material information, explicit uncertainty and suitable methods. Control banding can guide priorities; sampling and analytical techniques must be justified by competent personnel.
3. Apply the hierarchy of measures: substitution or use of less dispersible forms (suspensions, granules), closed systems, localized extraction with HEPA filtration and work organization.
4. Define individual protection for each task, wet cleaning procedures and waste management, and delimit and mark the areas.
5. Inform and train exposed people, record exposures and apply Royal Decree 665/1997 where its legal criteria for carcinogens, mutagens, reprotoxic agents or listed processes are met.
6. Establish specific health surveillance and retain exposure records for the required periods.
7. Review the assessment with the new toxicological information, process changes and the updated regulations and INSST guidelines.

A management system can support inventories, documentation, tasks, measures and follow-up where it has suitable functions and data. It does not itself determine hazard or legal compliance. Clinical data remain within healthcare channels; the organisation receives the necessary preventive conclusions while respecting confidentiality.

Limits and common mistakes

1. Treating nanomaterials like the conventional material of the same name and apply their mass limit values ​​without considering size and reactivity.
2. Relying on safety data sheets that do not describe nanoforms or their specific hazards.
3. Handling nanopowders in the open, using dry sweeping or compressed air, and treating contaminated waste as ordinary waste without assessment.
4. Using respiratory protection without suitable high-efficiency filters or proper fit, or as the sole measure instead of closed systems and extraction.
5. Failure to record exposures or establish health surveillance due to the absence of specific limit values.
6. Forgetting the fire and explosion risks of certain nanopowders.

Scientific evidence on nanomaterials is evolving; this fact sheet is for informational purposes and should be supplemented with specific information for each material.

Regulatory and reference framework

• Royal Decree 374/2001, of April 6. Protection against risks related to chemical agents during work.
• Royal Decree 665/1997, of May 12. Protection against exposure to carcinogenic agents during work.
• Regulation (EC) 1907/2006 (REACH) . Registration, evaluation, authorization and restriction of chemicals.
• Regulation (EU) 2018/1881 . Amends the annexes to the REACH Regulation to include nanoforms of substances.
• NTP 1172. Nanomaterials: preventive measures . Technical, organizational and protective measures against nanomaterials.
• NTP 877. Risk assessment for exposure to nanoparticles using simplified methodologies . Control band methods for nanomaterials.
• INSST. Nanomaterials . Thematic portal with documentation and frequently asked questions.

The definition of nanomaterial is set out in the European Commission Recommendation of 2022 on the definition of nanomaterial, which updates the 2011 one cited in the Prevention Technical Notes.

Paints with environmental claims: establish the composition

A paint described as environmentally friendly, low in solvents or capable of reducing pollution needs its own workplace risk assessment. Those descriptions do not demonstrate that it contains nanomaterials or that every method of use is harmless. Procurement should obtain information about ingredients, nanoforms, concentration and application conditions. Resins, preservatives, solvents and other agents also matter. An assessment cannot reduce a complex formulation to one marketing term or automatically transfer an environmental claim about the finished product into a conclusion about safety at work.

Identification should distinguish dispersed solid particles from dissolved substances and describe size, shape, coating and behaviour in the medium being used. A liquid dispersion is not equivalent to a molecular solution. The European recommendation of 2022 uses a particle-number-based distribution, with additional conditions concerning geometry and specific surface area; a commercial average size is insufficient. Specific duties must be checked against the applicable legislation. A horizontal recommendation does not, by itself, amend every sector-specific definition or place every small ingredient in the same legal category.

When choosing a substitute, compare the complete process: preparation, application, drying, cleaning and subsequent surface treatment. An alternative might reduce vapours while retaining an aerosol hazard, or reduce dust dispersion while introducing another hazardous agent. Keep the safety data sheet version, supplier clarifications and reasons for the decision. Insufficient information calls for resolving uncertainty and taking precautionary measures. It does not justify marking a product as safe because it carries an environmental label. The decision should reflect the work that people will actually perform with it.

Spraying, sanding and release throughout use

Exposure potential changes with the task. Opening and transferring dry powder, preparing a suspension, spraying it and sanding a cured coating are different scenarios. INSST NTP 1172 describes how vigorous agitation can generate aerosols even from suspensions, and how machining nanocomposites releases particles both with and without the incorporated nanomaterial. A solid finish therefore does not guarantee that nothing will be released during repair. Equally, it should not be assumed that all generated dust consists of free nanoparticles: that composition requires information and, where appropriate, characterisation.

Prevention starts by avoiding dispersive operations where a technically suitable alternative exists. Coating application may allow brushing, rolling or dipping instead of spraying. If spraying is necessary, containment and extraction should be designed around the actual process. Sanding calls for consideration of extraction at the tool and compatible methods that reduce dust generation. Particle filters do not, on their own, retain solvent vapours. Ventilation, filtration and respiratory protection must be selected for all relevant contaminants, with their combined effectiveness checked under representative conditions.

Assessment includes preparation, filter changes, removal of workpieces, cleaning and foreseeable breakdowns, as well as production time. Dried residues from a suspension can leave material that becomes airborne again. Define when and how the equipment can be accessed after the operation, rather than relying only on the aerosol no longer being visible. Instructions should reflect the conditions and manufacturer recommendations. A measurement during stable operation does not automatically represent a cleaning peak or an intervention with containment opened. Those activities need their own consideration in the work plan.

Cosmetics and pharmaceuticals: protecting both product and worker

In cosmetics, the finished-product safety assessment considers composition and intended conditions of consumer use. The 2023 SCCS guidance addresses characterisation, exposure and toxicology for that dossier. It does not replace assessment of the worker who receives raw materials, weighs concentrates or cleans equipment. A formulation applied to the skin by a consumer may present a different exposure scenario during manufacture. Product documentation provides useful information, but it must be applied to the material, route and task actually encountered at the workplace.

Pharmaceutical research and manufacturing must also consider other hazards associated with the formulation and process, including active ingredients or solvents where present. A requirement to keep the product clean does not demonstrate containment of a hazardous agent. A clean-air cabinet intended only to protect the sample can direct contaminants towards the person; NTP 1172 distinguishes that function from user protection. Selection of a cabinet or isolator should justify both requirements where they coexist and check compatibility with the substances and planned operations, rather than relying on the equipment name.

Before work starts, transfer, container opening, handling, decontamination and waste removal should be defined. Placing a balance under an airflow does not in itself establish safe weighing. Check operation, material placement, openings, procedures and maintenance, avoiding changes that undermine containment. Training should explain the response to an alarm or spill and the reporting route. Cleaning staff, maintenance personnel and external contractors need sufficient preventive information about the materials they may encounter. Their exposure cannot be assessed solely from the normal production operator’s routine or protective equipment.

Measuring particles without mistaking them for the target material

The 2022 NIOSH report combines industrial hygiene strategies to characterise exposure and emissions. Direct-reading instruments can associate particle variations with tasks, but alone they lack the specificity required to identify a nanoform. Personal sampling, composition analysis and microscopy may need to be combined according to the material and the question being investigated. A display showing particles per unit volume does not automatically indicate the concentration of the agent being used or demonstrate that every particle comes from the process under assessment.

The sampling plan should record times, tasks, locations, equipment and ventilation conditions. Ambient particles or other activities can affect readings. NIOSH cautions that area samples used to investigate dispersion or cross-contamination should not simply be subtracted from breathing-zone samples to calculate worker exposure. They must be interpreted according to their purpose. Mass concentration remains relevant for particular methods and criteria; size, number, composition or morphology can complement it. No single metric provides a universal answer, and results should retain the method, uncertainty and limitations needed for interpretation.

Control banding helps organise information and prioritise measures where uncertainty exists, but it does not certify acceptable exposure. NTP 877 is a historical reference from 2010 and should be read alongside later methods, without transferring its older instrumental limitations to current practice. Missing hazard data should be expressed as uncertainty in the result. Conclusions require justified criteria, competent personnel and review following change. Values recommended by foreign bodies should be identified as such. They must not automatically be presented as legally binding Spanish exposure limits or applied without checking the material and measurement method.

Waste, maintenance and health follow-up

The plan should include compatible closed containers, identification and removal that prevents dispersion or contamination of clean areas. NTP 1172 recommends precautionary treatment of nanomaterial-contaminated waste as hazardous, including filters and cleaning materials. That preventive recommendation should be distinguished from legal classification, which is determined through the list and properties specified in Spanish Law 7/2022. Nanoscale size alone does not resolve every waste code. Document the material, management procedure and information supplied to the authorised waste operator, including any relevant uncertainty about composition or hazardous properties.

Cleaning should prevent resuspension: dry sweeping and compressed air are unsuitable solutions. Wet methods require chemical compatibility and control of the resulting liquids; vacuuming requires equipment suited to the hazard and effective filtration. Filter changes can concentrate exposure and need a specific procedure. Personal protection should follow the assessment, including fit where required and safe donning and removal. A particle filter does not supply oxygen or automatically address simultaneous gas or vapour exposure. The response to contaminated equipment must be planned before it is dismantled or transferred to another work area.

Health surveillance should reflect specific risks and circumstances, with justified examinations and confidentiality under Article 22 of Spanish Law 31/1995. The word “nano” does not justify imposing an identical test package on everyone, and a normal clinical result should not be confused with effective ventilation. Preventive records retain materials, tasks, exposures and measures; clinical information stays within healthcare channels. A management system can assist where it has appropriate functions, but it does not automatically identify toxicity, classify waste or establish safety. Decisions still require competent interpretation and follow-up.