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J. Cosmet. Sci., 76.1, 1–8 (January/February 2025)
*Address all correspondence to Laura R. Muollo and John C. Warner, laura.r.muollo@gmail.com john@
johnwarner.org
The 12 Principles of Green Chemistry in Cosmetic Sciences
LAURA R. MUOLLO AND JOHN C. WARNER
VP Hairprint/True Colors (L.M.), CEO &CTO Technology Greenhouse (J.W.)
Accepted for publication January 28, 2025.
Synopsis
Consumers and regulatory agencies are applying more and more pressure on companies to create technologies
that address issues of health and environmental sustainability. There are many techniques and approaches to
describe, measure, and characterize the health and sustainability of a material or product. Green chemistry
is a mechanistic science that enables the design of products to avoid these issues. This manuscript describes
specific real-world examples utilizing the 12 Principles of Green Chemistry in cosmetic sciences.
INTRODUCTION
Well into the 21st century, consumer-facing companies have recognized the critical need
to address sustainability. The “WHY” is ever present in our culture. Evidence of the
changing climate is ever present.1 Images of plastics accumulating in the environment
are ever present.2 News of biodiversity loss and species extinction is ever present.3 News
of increasing incidents of cancer,4 birth defects,5 childhood asthma,6 and the impact of
endocrine disruptors7 on the human species is ever present. It is unlikely that anyone
today has not heard about and is likely convinced of the WHY we must be concerned
about sustainability. The “WHAT” of sustainability is equally clear. There are multiple
approaches (sadly, often in competition with each other) such as safe and sustainable by
design,8 circular economy9 and circular chemistry,10 planetary boundaries,11 and cradle to
cradle12 are all examples of various ways to characterize issues in sustainability through Life
Cycle Analyses.13 While each is subtly different, these approaches all illustrate various ways
to measure, characterize, and describe beneficial conditions, that we humans should strive
for to accomplish the goals of sustainability. While most efforts focus on the WHYs and
the WHATs of sustainability, stating the urgency of a crisis and providing mechanisms to
measure the crisis, while obviously important, do not offer any mechanism to SOLVE the
crisis. We also need the HOW to address sustainability challenges. This is the unique role
that Green Chemistry14 and its 12 Principles were designed to address. Green Chemistry is
defined as “the utilization of a set of principles that reduce or eliminate the use or generation
of hazardous substances in the design, manufacture, and application of chemical products.”

2 JOURNAL OF COSMETIC SCIENCE
The need for green chemistry has been recognized as a fundamental part of cosmetic
sciences since the inception of the field.15 The International Fragrance Association has
recently adopted a “Green Chemistry Compass” to help.16 Because Green Chemistry has
been around since the early 1990s, we will not attempt to summarize its history and
fundamentals here. Instead, this manuscript will use various advances in cosmetics sciences
to illustrate each of the 12 Principles of Green Chemistry.
It is important to point out at the outset that no individual principle of green chemistry
should be considered in isolation. Dividing aspects of sustainability into 12 Principles
allows us to consider different types of molecular mechanisms at a level that is actionable.
Of course, a final product must combine each of these concepts in totality, but there is still
much work to be done. We have not yet invented most of the necessary new mechanisms. It
will take decades to make significant headway, and hopefully the examples illustrated here
will help give some direction and inspiration to future inventors to move the field forward.
It is well understood that many examples demonstrate more than one principle of Green
Chemistry, the choice of which principle to focus on is mostly for clarity.
Principle 1: It is better to prevent waste than to treat or clean up waste after it is formed.
Thie first principle acknowledges the US Pollution Prevention Act of 1990.17 This legislation
underscored the importance of source reduction as a fundamental part of pollution
prevention. Banjamin Franklin’s adage “an ounce of prevention is worth a pound of cure”
resonates as common sense.18 Illustrative of this principle is the issue of microplastics in
cosmetic formulations. There has been a great deal of information describing the hazards to
humans and the environment because of intentionally added microplastic beads.19 Efforts
to identify mineral and plant product alternatives are numerous.20 Specific examples using
chitosan21 and silk22 are promising.
Principle 2: Synthetic methods should be designed to maximize the incorporation of all
materials used in the process into the final product.
Atom Economy23 and its related concept environmental impact factor24 focus on
distinguishing between the yield of the product in a manufacturing process versus the
reactants that do not end up in the product. These are materials necessary to the reaction. For
example, in the reaction A plus B forms C and D, if one assumes compound C is the desired
product, D is a necessary coproduct. Even if one accomplishes the quantitative conversion of
the desired material C, by molecular definition, we MUST also form an equivalent amount
of the unnecessary coproduct D. An illustrative example of atom economy is the synthesis
of some biobased surfactants.25 Stubbs, Yousaf, and Khan describe the atom economy seen
in the synthesis of alkyl polyglucosides26 and sucrose esters27 surfactants.
Principle 3: Whenever practicable, synthetic methodologies should be designed to use and
generate substances that possess little or no toxicity to human health and the environment.
Principles 3 and 4 are closely related concepts. The third principle focuses on hazard during
the manufacturing forces and the fourth principle focuses on the toxicity of the product
itself. A good example of this principle is the use of ethylene oxide in the manufacture
of polyglycol ethers.28 Glycidyl methyl ether has been proposed as a safer alternative to
ethylene oxide for designing ethoxy free surfactants.29 Another route to avoid ethylene
oxide is to synthesize linear polyglycerols.30
Principle 4: Chemical products should be designed to preserve efficacy of the function
while reducing toxicity.