While chemical surfactants undeniably exhibit efficiency and versatility, it’s crucial to acknowledge the substantial drawbacks associated with their widespread use. The environmental impact of chemical surfactants, particularly those derived from non-renewable petrochemical sources, cannot be overlooked. Their production and disposal contribute to pollution, posing long-term threats to ecosystems. Moreover, the limited biodegradability of certain chemical surfactants raises concerns about their persistence in the environment, potentially causing ecological harm.
Health considerations also warrant attention, as some chemical surfactants may carry risks, especially when used in high concentrations or in products that come into direct contact with the skin. These concerns align with a growing awareness of the need for more sustainable and eco-friendly alternatives in the face of increasing environmental challenges.
While chemical surfactants have played a pivotal role in various industries, their overall impact prompts a reevaluation of their use. The ongoing quest for greener and safer alternatives reflects a collective acknowledgment that, indeed, the environmental and health concerns associated with chemical surfactants merit serious consideration.
What is a surfactant?
A surfactant, short for “surface-active agent,” is a compound that lowers the surface tension between two substances, such as a liquid and a solid or between two liquids. Surfactants have hydrophilic (water-attracting) and hydrophobic (water-repelling) parts in their molecular structure. This dual nature allows them to interact with both water and oils, facilitating the dispersion and stabilization of immiscible substances.
im·mis·ci·ble
/i(m)ˈmisəb(ə)l/
adjective
(of liquids) not forming a homogeneous mixture when added together.
Surfactants play crucial roles in various applications, including cleaning products, detergents, emulsifiers, foaming agents, and in industries like agriculture, pharmaceuticals and cosmetics. They can help break down and remove grease and dirt, enhance the spread of liquids, and stabilize mixtures of different substances.
Biosurfactants and Chemical Surfactants: 5 Key Differences
Biosurfactants: |
Chemical Surfactants: |
| Natural Origin: Biosurfactants are produced by living microorganisms such as bacteria, yeast, and fungi. | Synthetic Origin: Chemical surfactants are artificially synthesized through chemical processes. |
| Biodegradable: They are typically biodegradable and environmentally friendly, making them more sustainable. | Variable Biodegradability: While some chemical surfactants are biodegradable, others may have environmental concerns due to their synthetic nature. |
| Diverse Sources: Biosurfactants can be derived from a variety of renewable resources, including plants and microorganisms. | Petrochemical Sources: Many chemical surfactants are derived from petrochemicals, which are non-renewable resources. |
| Varied Applications: Biosurfactants have a wide range of applications, including agriculture, animal care, environmental remediation, and various industrial processes. | Common Industrial Use: Chemical surfactants are widely used in industries such as cleaning products, detergents, and personal care items. |
| Complex Structure: They often have complex molecular structures and exhibit unique functionalities. | Simpler Structure: They often have simpler molecular structures designed for specific purposes. |
In summary, biosurfactants are natural, biodegradable and sourced from living organisms, offering sustainability advantages. Chemical surfactants, on the other hand, are synthetic and may have varying degrees of biodegradability, with a more common use in traditional industrial applications. The choice between them depends on the specific requirements of the application and the emphasis on environmental considerations.
Biosurfactant Adoption
Although biological surfactants have been used thousands of years before the invention of chemical surfactants, nowadays the chemical analogs are more widespread because are thought to be cheaper. Chemical surfactant usage has been growing quickly in the last several decades. In 1970, the worldwide production of surfactants was 10 million tons, reaching 40 million tons in 2000 and 5 billion tons in 2018.
Concerns of Chemical Surfactants
About 60% of surfactants are used as detergents and compounds for personal care products. Additionally, surfactants are used in almost every other human activity and product. Some other applications include pharmaceutical and supplements, oil and gas, agriculture, personal care and cosmetics, coatings and paintings, textile, food, construction and more.
However, there are many concerns regarding the usage of chemical surfactants that led scientists, manufacturers and policymakers to the need for natural surfactants, such as biosurfactants, which can be produced in equally large amounts and at a low price.
Facts at a Glance
Environmental Impact
- After use, residual surfactants are discharged into sewage systems or into surface waters. As a result, some of them are dispersed into soil, water or sediment. When present in high concentrations in water, surfactants may damage plants and animals.
- Small concentrations, although not causing death, were demonstrated to have a toxic effect on fish. Cyprinus carpio, after exposure to surfactant at concentration 0.01 mg/L, moved 5 times slower and consumed 2.8 times more oxygen (Barbiery et al., 1998).
- Apart from acute toxicity, some surfactants, due to their chemical structure, have the ability to bind to biomolecules such as proteins, peptides, and DNA (Bhattacharya and Mandal, 1997).
- The production of surfactants contributes to global warming because the waste products contain significant amounts of NOx, CO2, SO2, hydrocarbons, waterborne wastes and solid wastes (Pittinger et al., 1993).
- A concentration of the surfactants higher than 0.1 mg/L causes foam formation, preventing the dissolving of oxygen in water; leading to organisms’ death (Yuan et al., 2014).
Human Toxicity
- When a contaminated aquatic animal is eaten by a human, enzyme production in the human is disrupted, weakening human’s immune system (Yuan et al., 2014).
- Perfluorinated surfactants are found in drinking water and the concentrations do not differ significantly from the concentration of these surfactants in the surface water (Exner and Farber, 2006).
- Although the concentrations observed in drinking water were not acutely toxic, the perfluorinated surfactants, as well as sodium dodecylbenzene sulfonate (SDBS), have an ability to accumulate in human tissues such as liver and blood, causing accumulative carcinogenic and reproductive interference effects (Exner and Farber, 2006).
- Long-term use of detergents and cleaning products containing surfactants may cause skin irritation and increase the risk of atopic dermatitis, psoriasis and eczema in individuals with sensitive skin (Cowley and Farr, 1992; Draelos et al., 2013; Yuan et al., 2010).
- Some cationic surfactants, which are second most used surfactants, damage human lymphocytes and lyse human cells in concentrations even below the CMC (Antoni and Szabo, 1982; Partearroyo et al.,1990).
Future Trends
Statistical analyses of surfactant concentrations in the environment reveal that they are found in concentrations higher than their predicted, no-effect concentrations. As was concluded in the analytical report on the global market of chemical surfactants, the market’s growth is predicted to slow due to several factors affecting the massive application: volatility in raw material prices, regulations on environmental issues, pollution control laws, the toxic nature of surfactants and an increased demand for “green” products.
As disagreements regarding the safety of other commonly-used surfactants continue, it is expected that additional surfactants will be revealed to be highly toxic and, consequently, banned.
It was suggested that all these trends lead to the increased demand for bio-based surfactants, which are going to replace chemical surfactants.
Because biosurfactants are naturally-occurring, they are safe, favorable to the environment and allow the use of claims including “green” and “organic” for products, making them a valuable substitute for chemical surfactants. Biosurfactants were shown to be more effective than chemical surfactants and due to lower CMC are more economically beneficial.
READ MORE: Biosurfactant Applications: Powerful, Sustainable Solutions for Every Industry
Biosurfactants are organic compounds produced by microorganisms. These versatile molecules possess unique surface-active properties, making them invaluable across a spectrum of industries. Unlike their synthetic counterparts, biosurfactants are biodegradable, environmentally friendly and exhibit low toxicity. These bio-based agents are ushering in a new era of industry-wide eco-innovation.