Recent developments in nanomaterials in care products

Consumers have purchased products that contain nanoparticles, which can cause intentional or unintentional inhalation (nanoparticles) when used. The impact of inhaling nanoparticles on human health has attracted attention mainly through case reports of occupational exposure risks in certain positions.

The effects of inhaling aerosols containing nanoparticles on human health have mainly been studied through case reports of occupational exposure risks. There are reports that after the human body inhalation of Ag, it can lead to silver poisoning. However, this has not been proven. In studies where workers making nano silver were exposed to Ag concentrations ranging from 3.5×10-4 to 1.35×10-3 mg /m3, inhalation data of nano TiO2 were well documented in pigment factories.

In one study, workers were exposed to anatase and rutile TiO2 simultaneously while performing common work tasks (research, micronization, and calcination). The average aerosol concentration at this time was 1.98×104 particles /cm3(or 0.65 mg /m3), of which 70%-82% were nano-sized. Breath coagulation (EBC) measured by workers showed an increased concentration of 24.1±1.8µg/L of titanium, a lower pH, and an increased concentration of leucotrienes, no detectable titanium in urine, and no significant changes in respiratory function or allergy symptoms.

In the earlier study, no significant changes were observed in respiratory function and metal smoke fever symptoms after continuous inhalation of 0.5 mg /m3 or 4.6×107 particles /cm3 of ultrafine ZnO particles for 2 hours. A recent study of human volunteers reported that inhalation of 1 mg /m3(2×106 /cm3) ZnO particles for 4 hours showed a dose-dependent increase in blood inflammatory markers, reactive proteins, and serum amyloid A.

Note that the conditions involved in this study are two orders of magnitude larger than the concentration (3.4×104 particles /cm3) and exposure time (1 minute per session) expected for the use of nano cosmetic powder.

While it should be ideal to study both short-term and long-term toxicity data, current studies in humans only involve short-term exposure, and long-term exposure studies are limited to animals. In addition, personal care products containing nano-components do not have such monitoring of use after marketing. Therefore, further research is needed to predict the consequences of long-term low dose human exposure to nanocomponents.

Data from rodent studies indicate that, in the long term, nanomaterials show toxic effects on their reproduction and development. However, the concentrations of nanomaterials used in these studies were significantly higher than expected in personal care products. Many of the studies reviewed here investigated the acute effects of using personal care products on the market. The effects of personal care formulations on the toxicity of nanomaterials are often not studied in animal experiments. In contrast, animal studies have mostly reported toxicity from a single component, while nanoparticles are usually dispersed in water or in a carrier.

Therefore, more research on the toxicity of product mixtures is necessary to better understand, for example, how interactions between different inorganic and organic active ingredients contained in products such as sunscreens and cosmetics may cause photoirritation or photoanaphylaxis.

Toxicity tests for individual substances typically cost between $70,000 and $4.5 million; Therefore, if the data collected by the industry is published or made available in a common repository, the use of resources can be optimized.

In addition, there has been much discussion about whether new testing methods are needed to assess the toxicity of nanoparticles. Although standardized methods developed like the OECD test are generally accepted for relevant testing of nanomaterials, few organizations report using these methods. Standard operating procedures are important for the consistency of nanotoxicological data. In addition to standardization, common concerns in toxicological studies of nanomaterials include lack of adequate physicochemical properties, lack of use of positive controls, inadequate dose quantification, and lack of in vivo confirmation of in vitro results. The U.S. Food and Drug Administration (FDA) has not indicated which testing methods it considers appropriate to determine the safety of nanoscale ingredients in cosmetics.

In Europe, cosmetic regulations prohibit the use of animal testing to evaluate chemicals used only in cosmetics. This ban has stimulated the use of silicon, chemical and in vitro methods. Future tests will reveal the relevance of the data generated by these alternative methods to reactions in humans.

Sustainability of nanomaterials for personal care products

The sustainable development of nanoscale personal care products affects the long-term prospects of the industry and thus the circumstances and ways in which consumers are exposed to nanomaterials. The literature defines sustainability as broadly encompassing three areas important to long-term industrial development: the environmental domain, the social domain and the economic domain.