Health and safety hazards of nanomaterials

The health and safety hazards of nanomaterials include the potential toxicity of various types of nanomaterials, as well as fire and dust explosion hazards. Because nanotechnology is a recent development, scientists are still studying the effects of being exposed to nanomaterials and trying to learn what levels of exposure might be safe.

One of the biggest concerns is breathing in nanomaterials. Studies with animals have shown that some nanomaterials can cause problems in the lungs, such as inflammation, fibrosis, and even carcinogenicity. It is also important to be careful about skin contact, swallowing nanomaterials, and the risk of dust explosions.

To keep people safe, special guidelines have been created. These include using safer forms of nanomaterials (substitution), setting up good ventilation systems (engineering controls), and wearing protective gear (personal protective equipment). Some materials have safe limits for how much can be in the air (occupational exposure limits), and scientists can measure exposure levels using standard methods (industrial hygiene sampling). Regular health checks for workers (occupational health surveillance) can also help protect their health. Recently, there is growing worry about microplastics and nanoparticles that come from plastic containers.

Background

Nanotechnology is the manipulation of matter at the atomic scale to create materials, devices, or systems with new properties or functions. It has potential applications in many areas, such as energy, healthcare, industry, and consumer products. Nanomaterials are tiny materials with at least one dimension smaller than 100 nanometers, and they often behave differently from larger materials.

Because nanotechnology is a recent development, we are still learning about how nanomaterials might affect our health and safety. Researchers are studying this to understand safe exposure levels. Special care is needed when handling these materials, especially in labs and factories, to protect workers. A good way to manage risks is to think about safety early in the design process, known as the Safe by Design approach, which helps prevent problems before they start.

Hazards

Main article: Nanotoxicology

Breathing in nanomaterials is a big concern. Tiny particles can get deep into our lungs and even enter the blood, reaching other parts of the body. Studies with animals have shown that some nanomaterials can cause lung problems, like swelling and thickening of the lung tissue. There is also worry that these particles might cause cancer, but more research is needed to understand the risks for people.

Nanomaterials can also be dangerous if they catch fire or explode. Very small particles, especially metal ones, can explode more easily than larger particles. They might also create sparks or short circuits, which can start fires. Scientists are still learning how likely these dangers are and how to keep people safe while working with nanomaterials.

Hazard controls

Controlling exposures to hazards is the best way to protect workers. The hierarchy of hazard control offers steps to reduce the risk of illness or injury. The most effective methods include elimination of the hazard, substitution with safer materials, engineering controls that keep workers away from hazards, administrative controls that change how workers behave, and personal protective equipment worn by workers.

Prevention through design means planning safety into the design of materials and processes early on. This helps protect worker health throughout the life cycle of materials and makes safety more cost-effective. Using hazard controls early can also save time and improve product quality.

Elimination and substitution

Elimination and substitution are the best ways to control hazards, especially during the design phase. While nanomaterials often cannot be replaced because of their special properties, it may be possible to choose properties like size, shape, or surface charge to make them safer. Other materials, such as solvents, can also be replaced with safer options.

Engineering controls

Main article: Engineering controls for nanomaterials

Engineering controls are physical changes to the workplace that keep workers away from hazards. These include enclosing hazardous materials or using ventilation and filtering systems to remove contaminated air. Engineering controls work well when other methods are not possible. They are often passive, meaning they work without constant worker action, which helps keep exposure levels low.

Administrative controls

Administrative controls involve changing worker behavior to reduce hazards. This includes training on safe handling and storage of nanomaterials, using proper labeling and signage, and promoting a strong safety culture. Administrative controls can support engineering controls when needed. Good practices include cleaning with wet-wiping methods, avoiding free particle handling, and following normal safety rules like hand washing and proper hazardous waste disposal.

Personal protective equipment

Personal protective equipment (PPE) is worn by workers and is the last line of defense. It is used when other controls are not enough or during emergencies. Typical PPE for chemicals, such as long pants, long-sleeve shirts, closed-toed shoes, safety gloves, goggles, and laboratory coats, is also suitable for nanomaterials. Nitrile gloves are preferred over latex gloves. Respirators with N95 or P100 filters can capture nanoparticles, but surgical masks are not effective. In the United States, special rules apply to the use of respirators.

Industrial hygiene

An occupational exposure limit (OEL) is the highest safe amount of a harmful substance that workers can be exposed to in the air at work. As of 2016, exact OELs had not been set for most nanomaterials. Some groups, like the British Standards Institute and the Institute for Occupational Safety and Health in Germany, have set OELs for a few nanomaterials. By 2021, the U.S. National Institute for Occupational Safety and Health had suggested safe limits for three types of nanomaterials:

• 1.0 μg/m³ for carbon nanotubes and carbon nanofibers
• 300 μg/m³ for ultrafine titanium dioxide
• 0.9 μg/m³ for silver nanoparticles

Special masks can help protect workers from these materials. When there are no set limits, some rules can help decide how to keep workers safe.

Exposure assessment is how we check if workers are coming into contact with harmful materials. This can be done by placing small devices near workers to measure particles in the air. These devices can count particles and collect samples to study later. Not all devices work well for very small particles, so it’s important to choose the right tools. Scientists have found that the size and shape of nanoparticles can affect how harmful they are.

Regulation

Main article: Regulation of nanotechnology

In the United States, different agencies help keep nanomaterials safe. The Food and Drug Administration looks after nanomaterials used in food, medicines, and beauty products. The Consumer Product Safety Commission makes sure everyday items are safe and may require special labels for risky materials. Workplace safety is handled by the Occupational Safety and Health Administration, which sets rules to protect workers and requires companies to share important safety information.

Other countries also have their own rules. In the European Union, nanomaterials are regulated under chemical laws that require companies to share information about their products. The United Kingdom has special rules for powders that could cause explosions.