Lab Safety Guideline: Tetramethyl Ammonium Hydroxide
Work with tetramethyl ammonium hydroxide solutions in a lab
Nanomaterials
Summary
How to work with nanomaterials and nanoparticles.
Who is this for?
Lab and research staff, including lab managers.
Nanomaterials and nanoparticles
Nanomaterials and nanoparticles are human-engineered particles with at least one dimension between 1 and 100 nanometers. They can be made of base materials like carbon, silicon, and various metals.
Nanoparticles have different properties than their respective bulk materials, including increased strength, conductivity, fluorescence, and surface reactivity.
Examples of nanomaterial research and work include:
- Biological, chemical, environmental, and mechanical engineering.
- Biology, biochemistry, microbiology, and cell culture work.
- Chemistry, physics, and material science.
- Medical fields and antineoplastic drug implants.
- Nanoparticle synthesis.
Materials like welding fumes, volcanic ash, motor vehicle exhaust, and combustion products naturally create nanoparticles known as ultrafine particles.
Working with nanomaterials
Ultrafine particles and nanoparticles are more toxic than larger particles when compared by mass. Nanoparticles can cause more pulmonary inflammation, tissue damage, and lung tumors than larger particles.
Nanoparticle toxicity depends on solubility, shape, surface area, and surface chemistry.
- Nanoparticles are deposited into the lungs more than larger particles. Nanoparticles can move from the lungs to other organs through the bloodstream and can also cross the blood-brain barrier. They follow airstreams and can easily collect in standard ventilated enclosures like fume hoods and biosafety cabinets (BSC) with high efficiency particulate air (HEPA) filters.
- Nanoparticles may be able to penetrate intact skin and damage cellular function, but it is unclear if occupational exposure presents these risks.
Nanoparticle toxicity thresholds are still unclear.
Inhalation
- Perform synthesis work in an enclosed reactor or glove box to prevent airborne exposure.
- Remove processing materials from reactors in a fume hood. If practical, perform this work in an enclosure with a HEPA filter (such as a BSC).
- Perform maintenance on reactor parts that could release residual particles in a fume hood. If practical, perform this work in a hood with a HEPA filter (such as a BSC).
- Perform work with nanomaterials in solution form in a fume hood. If practical, perform this work in a hood with a HEPA filter.
- Use research techniques that emphasize slowly and carefully handling nanomaterials to prevent aerosolization.
Ingestion
Follow normal hygiene practices:
- Avoid hand-to-mouth contact.
- Wear gloves if there is a potential exposure risk to nanoparticles.
- Wash your hands immediately after removing your gloves.
- Do not eat, drink, smoke, or apply cosmetics in the lab or before washing your hands.
Injection
Follow lab sharps minimization work procedures.
Skin contact
- Wear gloves when handling nanoparticles in solution.
- Consider wearing disposable nitrile gloves during regular lab procedures that do not involve extensive skin contact. You may need to wear specific types of gloves during certain procedures.
- For solutions, wear gloves with good chemical resistance to the solute.
- For dry particles, wear sturdy gloves like nitrile gloves with good integrity.
- Double-glove for procedures with extensive skin contact.
- Ensure there is no skin exposed around your hands and wrists.
- Regularly check your gloves for damage like holes and cracks.
- Wash your hands immediately after removing your gloves.
- Use a damp cloth to wipe up any remaining powders.
- Use absorbent materials appropriate for the solute to clean up large spills. Wear a HEPA-filtered respirator and double-glove.
- Never clean up nanomaterials by dry sweeping or using compressed air.
Waste disposal contractors coordinate nanomaterial disposal.
- Never dispose of nanoparticle waste in the regular trash or down a drain.
- Dispose of waste and contaminated debris in the same way as the base material. For example, dispose of carbon nanotubes as carbon and metallic particles like their base metal.
- Label all waste with the base metal or solute and identify that it contains nanomaterials.
- For dry nanoparticle waste, use a sealable container that stays closed.
- Manage nanoparticles in solution as a solution of the solvent and the parent nanomaterial. For example, handle flammable solvents as flammable waste materials.
Nanomaterial risk assessments
EHS nanomaterial risk assessments include:
- Identifying hazards by contacting people in your lab who work with nanomaterials.
- Visiting your lab to review processes and observe experiments.
- Evaluating exposure risks by reviewing grinding, etching, sonicating, mixing, synthesis, or pouring tasks that could release nanomaterials.
- Characterizing risks by assessing risk levels based on how you use nanomaterials and potential exposure length.
- Recommending applicable engineering controls like BSCs, enclosures, fume hoods, glove boxes, HEPA-filtered enclosures, and local exhaust ventilation.
Related resources
Find documents and online tools to manage nanomaterial and nanoparticle safety.
Sink Disposal and Wastewater Discharge Poster
Printable poster about wastewater discharge and sink disposal requirements
EHS support
EHS conducts nanomaterial risk assessments.
Contact lab_safety@harvard.edu or your Lab Safety Advisor (LSA) for more information about nanomaterials, including:
- Developing safety procedures.
- Engineering controls.
- Risk assessments.
- Waste disposal.