Personal Care Product

2.6 Personal care and cosmetics

Personal care products and cosmetics are widely used throughout the world in huge amounts. It results in the continuous invisible release of personal hygiene and cosmetics products or ingredients into the environment. Altogether these impact on the life of living beings as these are bioactive, highly persistent in the environment, and can also bioaccumulate [58,59]. Personal care and cosmetics include any product which is applied on the external part of the body such as skin, nails, hair, lips, and external genital organs, or oral hygiene such as teeth and mucous membrane of the oral cavity, in order to make them clean, protect from germs, prevent bad odor, change in appearance, and keep in good condition [60]. Unlike pharmaceutical drugs, personal care and cosmetic products can be consumed only for external usage. Therefore they are more likely to enter into the environment in large quantities due to human activities, for example, during bathing or washing and give more trouble to the ecological systems [61–63]. Soaps, hair dyes, nail paints, fragrances, emulsifiers, ultraviolet absorbers, acrylates, preservatives, and antioxidants are the common examples of daily use personal care and cosmetic products. Some of these are hazardous for health and heavy exposure of such chemical cosmetics can cause cancer, endocrine disruption, mutation, allergy, and reproductive toxicity [64].

Abstract

Personal care products often contain nanosized components, such as nanoscopic vesicles. Nanosized metal oxides and nanoencapsulated UV organic filters have brought many attentions and technological advantages to sunscreen cosmetic products. Nanosized metal oxide particles are recently in- and extensively used to broaden the protection spectrum and increase the SPF factor by reflecting, scattering and/or absorbing UV radiation.

Modern sunscreens contain mineral filters—insoluble titanium dioxide (TiO₂), zinc oxide (ZnO) or ceria (CeO₂) and zirconia (ZrO₂) nanoparticles. Nanosized metal oxides provide superior UV protection by reflecting physically the light and eliminating the unsightly white residues. The inclusion of nanomaterials in day care products (especially facial cosmetics, i.e., creams) has prompted concern regarding the systemic absorption of these particles. An extensive discussion is presented regarding this issue.

Nanoencapsulation of traditional organic UV filters is a more recent technological approach to improving the skin preservation, photostability and UV blocking ability of the free radicals/species. Especially, nanostructured polymers and solid lipid carriers (SLC) are interesting carriers for organic filters in sunscreens. Nanoencapsulation enhances the retention of organic sunscreens in the upper layers of the skin and alters the penetration and release profiles of the active molecule according to the novel design and material of the nanoparticle.

16.5.22 Polyolefins/Poly(ethylene oxide)

Personal care products, such as baby diapers, sanitary napkins, adult diapers, etc., are generally constructed from a number of different components and materials. Such articles typically have some portion, usually the backing layer, that is composed of a film constructed from a liquid repellent material.

This repellent material is appropriately constructed to minimize or prevent the exuding of the absorbed liquid from the article and to obtain greater utilization of the absorbent capacity of the product. The liquid repellent film commonly used includes plastic materials such as poly(ethylene) films.

Polymer blends of polyolefins and poly(ethylene oxide) are melt processable but exhibit very poor mechanical compatibility. This poor mechanical compatibility is particularly manifested in blends having greater than 50% of polyolefin. Generally the film is not affected by water since typically the majority phase, i.e., polyolefin, will surround and encapsulate the minority phase, i.e., the poly(ethylene oxide).

The encapsulation of the poly(ethylene oxide) effectively prevents any degradability and/or flushability advantage that would be acquired by using poly(ethylene oxide). An inverse phase composition, characterized by a continuous phase of poly(ethylene oxide) and a dispersed phase of polyolefin, can be produced by reactive extrusion.

The components, the polyolefin, poly(ethylene oxide), poly(ethylene glycol)methacrylate or 2-hydroxyethyl methacrylate and the initiator 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, i.e., Lupersol™ 101 or Interox™ DHBP can be premixed before heating, and blending to produce an inverse phase composition. Alternatively, the components may be added simultaneously or separately to a reaction vessel for melting and blending. Ideally, the polyolefin and poly(ethylene oxide) should be melt blended before adding monomer or initiator. The monomer and initiator may be added to the molten polymers separately or combined in a solution comprised of the monomer and the initiator.

In a reactive extrusion process, it is desirable to feed the polyolefin and poly(ethylene oxide) into an extruder before adding monomer further down the extruder and adding initiator even further down the extruder. This sequence facilitates mixing of the monomer or mixture of monomers into the polymers before the initiator is added and radicals are created [177].

4.4 Removal of incipient contaminants from wastewater

Pharmaceutical and personal care products (PPCPs), e.g., antibiotics, hormones, and other antimicrobial agents (triclosan (TCS), acetaminophen (AAP), and ibuprofen (IBU)), generally come from the pharmaceutical industries, sewage, and hospitals. The environmental endocrine disruptors (EEDs) like bisphenol A (BPA), dichlorodiphenyltrichloroethane (DDT), vinclozolin, and diethylstilbestrol (DES) come from plastics, pesticides, fungicides, and pharmaceutical industries. The persistent organic pollutants (POPs) such as pesticides, industrial chemical waste, and by-products are organic pollutants that affect human health and the environment adversely and are considered as forever chemicals. These PPCPs, EEDs, and POPs are known as emerging pollutants/incipient contaminants present in the environment. Even at low concentrations in the environment, from ng L^− 1 to μg L^− 1, they can cause severe adverse effects on human health as well as the environment (Liu et al., 2015). Many researchers are focused on the elimination of these pollutants from the environment, especially from water sources. Wang et al. fabricated a CNT-integrated PVDF membrane for the elimination of PPCPs like TCS, AAP, and IBU from contaminated water sources with more than 90% rate of filtration (Wang et al., 2015). The filtration rate depended on the aromatic rings present in the compound and the surface area of the CNTs. The compound with the more aromatic ring, e.g., AAP, had a higher filtration rate, up to 95%, whereas TCS had a smaller filtration rate of 10%, as it carries fewer aromatic rings. The membrane uses MWCNTs in order to filter more PPCP compounds as compared to SWCNTs, because MWCNTs have more surface area than SWCNTs. We conclude that the CNT-integrated PVDF membrane is capable of eliminating more PPCPs from contaminated water without changing the filter for a long time, because of the comparatively low concentration of the compounds in contaminated water.

15.5.1.2 Micropollutants

Micropollutants encompass pharmaceuticals, personal care products (PPCPs) and endocrine-disrupting compounds (EDCs) bearing various functional groups. They have been detected in surface and ground waters, and even sometimes in drinking water. Trace concentrations of PPCPs and EDCs in water have raised substantial health concerns. There is also an abundance of residual drugs such as antibiotics, cardiovascular, antiinflammatory drugs, and diuretics in water. The injudicious use of pesticides has introduced organophosphate (e.g., glyphosate), N-methyl carbamates, organochlorine, biological insecticides, chlorophenoxy, pentachlorophenol, nitrophenolic, arsenic containing fungicides, fumigants, and rodenticides in the ecosystem. Few phenolics and related aromatics, for example endocrine disrupting chemicals bisphenol A and ethynylestradiol (EE2) have raised global concern (Yuan et al., 2020).

4.10.1.1 Nanotechnology for the Man on the Street

Nanomaterials are found in health care products, personal care, and hygiene products, as nanomedicine and as additives in food.² US Project on Emerging Nanotechnology (PEN) lists at least 1628 (as of May 2016) consumer products that contain nanomaterials.³

Titanium dioxide-, silica-, and zinc oxide-based nanomaterials are commonly added into consumer products.³ While, chemically ZnO and TiO₂ are UV blockers through absorbing UVA and UVB radiation,⁴ the nanomaterials themselves are even smaller than the wavelength range of radiation. So TiO₂ and ZnO nanoparticles do not scatter the longer wavelength light of the visible light spectrum. Skin care manufacturers exploit this physical phenomenon so that when applied on skin, these nanomaterials would form an esthetically pleasing transparent layer on the skin while still able to provide the protection from UV radiation.^4–6

SiO₂ nanoparticles are also added to sunscreen not as an UV absorber but as a barrier between the skin and organic compounds in the sunscreen.⁷ Besides sunscreens, TiO₂, ZnO, and SiO₂ nanomaterials are also found in toothpastes, deodorants, moisturizers, creams, powder foundation, and face powders.⁸

The common nanomaterials, ZnO and TiO₂ have useful antimicrobial activity which makes them attractive candidates to be added into food and food paraphernalia. ZnO nanoparticles has strong antiseptic activities against Candida albicans⁹ and Escherichia coli¹⁰ and are directly layered on the inner surfaces of canned food for corn, meat, peas, and fish to preserve their quality and appearance.¹¹ TiO₂ nanomaterials are important food additives due to their photocatalytic antimicrobial properties. TiO₂ nanomaterials increases the shelf life of food.^12,13 TiO₂ nanopowders and nanotubes are added as part of the food packaging to inactivate harmful foodborne bacteria like Salmonella, E. coli and Staphylococcus.^14,15

3.1 Product Design

Absorbent core design in disposable absorbent personal care products has evolved significantly during the last twenty years. In 1960s the core design in almost all products used just fluff pulp, with or without a tissue insert, wrapped in a cellulosic nonwoven cover. Today’s absorbent products have many different materials including specific engineered composites, superabsorbents, deodorants, hydrophobic-hydrophilic balanced facings as well as unique structural designs to prevent leakage that originate through various pathways. The absorbent core in many ways is not a passive composite but interactive to body movements and the chemistry of body fluids. Whereas, it is not within the scope of this chapter to go into the detail of all the design aspects of disposable absorbent products, without any discussion of certain basic features of absorbent products a monograph on absorbent technology will not be complete.

There are many types of absorbent products, viz., personal hygiene care products, water, oil and hazardous chemical spill clean-up sponges, normal household wipes, industrial and food service wipes, wound care products and agricultural water control products. The discussion in this chapter is primarily centered around personal hygiene care because this category, by far, holds the largest share of the market. And in this category, the following specific types cover the major share of the market: baby diapers including training pants, feminine hygiene care including different kinds of sanitary napkins that fit the specific needs of consumers under different environmental and physiological conditions, tampons and adult incontinence pads.

Diapers have evolved from the fluff pulp absorbent core of mid 1980s with an average 51 g. per product to the thin diapers of the late 1980s with about 29 g. of fluff to the ultrathin diapers of the 1990s with an average of 16 g. of fluff. This reduction of fluff pulp had been possible not due to the advent of superabsorbent only but due to the unique designs of the products incorporating improved coverstock, leg cuffs, etc., that reduced the leakage.

Sanitary napkins, which led the radical changes in early 1980s with the introduction of thin maxis, have basically decreased thickness in the category by approximately 60%.

Incontinent absorbent products are slowly following the trend to thinner absorbent cores. This category is relatively new in the market and since its consumers are older population preference still tends to favor thicker products. This attitude of the consumers, however, is rapidly changing. The current incontinence pad has superabsorbent polymer, which helps to reduce the leakage, hence increases the dryness and that is comfort. Comfort improvement, discretion and cost improvement on storage and transportation will eventually gear its course towards thinner products.

The overall trend of disposable personal care absorbent products is thinness. Thinness results in overall comfort improvement but it also creates some problems in quality and protection. The superabsorbent particles usually have sand like feature, which is not comfortable when rubs against skin. Also, its gel like behavior when wet does not produce a desirable feeling if it comes in contact with the skin. A very thin absorbent product does not always maintain the contact of fluid proximity and thus creates occasionally leakage problems. Application of superabsorbent fibers that is being marketed recently in place superabsorbent polymer particles may alleviate some of the problems, such as sand like abrasion to skin or gel blocking. However, unless the cost of superabsorbent fiber is reduced significantly it would not find a wide scale application in disposable absorbent products.

“Acquisition” component allows the fluid to enter the absorbent structure quickly. This minimizes leakage since the fluid is entrapped into the structure and is not puddled on the top for very long. If the fluid puddles, any movement of the user that can cause a gap between body and the product will be the potential for leakage.

“Distribution” component provides the fluid spread out, primarily in the longitudinal direction of the product so that the absorbent structure can be better utilized. By having the fluid dispersed from the penetration zone, the absorbent structure will have a better probability of more fluid in that zone.

“Retention” component makes the fluid immobile once it is distributed longitudinally, so that it has less of a chance of flowing out of the product as a result of movement and pressure.

Even though this design concept is relatively simple to understand, it is not simple to develop in actual practice. A review of the patent literature indicates the major industry leaders in USA and Europe are actively pursuing research on various designs of absorbent composites as well as on materials that fit into the three-phase structural model.

3.4.1 Soap industry

Triclosan has had widespread use in household and personal care products as an antifungal and antibacterial agent for a long time.Triclosan contaminates groundwater, wastewater, and sediments and is toxic to aquatic lifeforms. Atar et al. (2015) reported a new molecular imprinted surface plasmon resonance (SPR) chemical sensor for selective detection of triclosan using an allylmercaptane modified gold SPR chip and imprinted poly(2-hydroxyethyl methacrylate-methacryloylamidoglutamic acid) nanofilm. The techniques used for the characterization of the unmodified and imprinted surface of SPR were Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), and contact angle measurements. The developed sensor had a linearity range of 0.05–1.0 ng/mL and a lower detection limit of 0.017 ng/mL (Atar et al., 2015).

Abstract

The presence of emerging contaminants such as pharmaceutical and personal care products in water has caused serious problem not only to environment but also to human health. Today, the use of nanomaterials has been identified as a potential approach to address this problem because of the unique properties of nanomaterials. This chapter considers the properties of nanomaterials for water treatment with a brief touch on challenges and prospects. Current approaches of nanomaterials in water treatment include photocatalysis, adsorption, membrane technique, and disinfection. Although there are a few challenges with the use of nanomaterials, these challenges are surmountable. However, nanomaterials are promising new generation means of water treatment with excellent and superb potentials for water treatment.

12.20.18 Safety assessment of personal care products/cosmetics and their ingredients

Nohynek et al. [19] reviewed the safety assessment of personal care products (PCPs) and ingredients that are representative and pose complex safety issues. PCPs are generally applied to human skin and mainly produce local exposure, although skin penetration or use in the oral cavity, on the face, lips, eyes, and mucosa may also produce human systemic exposure. In the EU, US, and Japan, the safety of PCP is regulated under cosmetic and/or drug regulations. Oxidative hair dyes contain arylamines, the most chemically reactive ingredients of PCP. Although arylamines have an allergic potential, taking into account the high number of customers exposed, the incidence and prevalence of hair dye allergy appears to be low and stable. A recent (2001) epidemiology study recommended an association of oxidative hair dye use and increased bladder cancer risk in consumers, although this was not confirmed by subsequent or previous epidemiologic investigations. The results of genetic toxicity, carcinogenicity, and reproductive toxicity studies suggest that modern hair dyes and their ingredients pose no genotoxic, carcinogenic, or reproductive risk. Recent reports suggest that arylamines contained in oxidative hair dyes are N-acetylated in human or mammalian skin resulting in systemic exposure to traces of detoxified, that is, nongenotoxic, metabolites, whereas human hepatocytes were unable to transform hair dye arylamines to potentially carcinogenic metabolites. An expert panel of the International Agency on Research of Cancer (IARC) concluded that there is no evidence for a causal association of hair dye exposure with an elevated cancer risk in consumers. Ultraviolet filters have important payback by protecting the consumer against adverse effects of UV radiation; these substances undergo a rigorous safety evaluation under current international regulations prior to their marketing. Concerns were also raised about the safety of solid NPs in PCP, mainly TiO₂ and ZnO in sunscreens. Nevertheless, current proof suggests that these particles are nontoxic, do not enter into or through normal or compromised human skin and, therefore, pose no risk to human health. The increasing use of natural plant ingredients in PCPs raised new safety issues that require novel approaches to their protection evaluation similar to those of plant-derived food ingredients. For instance, the Threshold of Toxicological Concern is a promising tool to assess the safety of substances present at trace levels as well as minor ingredients of plant-derived substances. The potential human systemic exposure to PCP ingredients is increasingly predictable on the basis of in vitro skin penetration data. However, new confirmation suggests that the in vitro test may overestimate human systemic exposure to PCP ingredients due to the absence of metabolism in cadaver skin or misclassification of skin residues that, in vivo, remain in the SC or hair follicle openings, that is, outside the living skin. Overall, today’s safety assessment of PCP and their ingredients is not only based on science, but also on their respective regulatory status as well as other issues, such as the principles of animal testing. However, the record shows that today’s PCPs are safe and offer multiple profits to quality of life and health of the consumer. In the interest of all stakeholders, consumers, regulatory bodies, and producers, there is an urgent need for an international harmonization on the status and safety necessities of these products and their ingredients [19].