An Enzymatic Approach to Sustainable
Manufacturing of Personal Care Ingredients:
Reducing the Traditional Environmental Impact
of a Consumer Product’s Life Cycle
By Stephanie Clendennen and Jinghua Yuan
Enzyme-catalyzed manufacturing processes address an important
phase in the life cycle of a consumer product by helping brand
owners differentiate their products without compromising product
performance.
Consumers may not be aware, but a product’s carbon footprint is
about more than the source of the ingredients; it can also be related
to how those ingredients are transformed into the products we use
every day. There are five main phases in the life cycle of a consumer
product, all of which contribute to the carbon footprint: raw materials, manufacturing process, transportation, use, and end-of-life. See
Figure 1. Manufacturers have the most control over the first three
phases, while consumers largely control the last two phases.
The main points of this article are:
1. Sustainable ingredients can come from green manufacturing processes.
2. Enzyme catalyzed processes are an innovative new option that
can reduce the carbon footprint of personal care ingredients.
3. Certified sustainable raw materials (RSPO) can further improve
the environmental profile of these materials.
Introduction
Consumers are increasingly demanding more natural and
“greener” products. Although it’s difficult to find a single definition,
“natural” typically refers to the source of the raw materials, while
“green” refers to the process used to convert starting materials into
a finished ingredient. Today, buyers not only care about the ingredients inside their favorite products, but they also care about the
impact that manufacturing these products has on the environment.
Many consumers prefer to purchase environmentally friendly products, especially for their personal care and home needs 1).
Figure 1. Life cycle of a consumer product
To address the demand for more sustainable products, some cosmetics companies, more specifically, the companies who supply
them, are adopting a green process known as enzymatic processing.
This process is a major breakthrough in the “greening” of cosmetics
manufacturing because it reduces the amount of energy needed to
make cosmetics and eliminates solvents and other wastes.
Personal care and cosmetics products are an important part of our
daily lives. Consumers choose shampoo, body wash, cosmetics, and
sunscreens for the way they feel, smell, and perform. But what if we
could enjoy these same products made with a smaller environmental
footprint?
This article focuses on how enzyme-catalyzed manufacturing
processes, such as patented Eastman GEM™ technology, can help
reduce the environmental impact of some personal care ingredients,
providing a new solution to the traditional environmental impact of
the manufacturing phase of a consumer product’s life cycle.
When it comes to the cosmetics industry in particular, natural and
green labeling offers distinct marketing advantages. In fact, according to research firm Kline & Company, consumer demand for natural
cosmetics products grew 13.9 percent in 2011 alone.
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resins or modified silica particles. But enzymes can also be immobilized on other porous polymer surfaces, such as filtration membranes.
Discussion
Using enzymes to make cosmetic esters
Esters, including emollients, emulsifiers, and specialty performance ingredients, are an important class of personal care ingredients. In 2014, the estimated global market for emollient esters was
valued at over $1 billion 2). The cosmetics industry in North America
alone consumes an estimated 50,000 metric tons of emollient esters
annually, so the processes by which these esters are manufactured
have a significant environmental impact. While esters are a necessary ingredient for many personal care products, the chemical reactions used to produce esters are highly energy-intensive. Typically,
emollient esters are manufactured using strong acid catalysts at high
temperatures to favor ester production; unfortunately, these conditions often produce undesirable byproducts that must be removed
by energy-intensive purifications. Enzyme-catalyzed processes use
enzymes and closely-controlled conditions to make esters without
the energy-intensive high temperatures and strong acids traditionally required to produce them.
The polymer raw materials used to make filtration membranes are
different from the structural materials made into particles and there
are many commercial sources of membranes for industrial processes.
A membrane-bound enzyme can be used in multiple reactor configurations, including batch and continuous processing. Unlike the
standard practice with particle-supported enzymes, the lifetime of a
membrane support can be extended by stripping spent enzyme
from the surface using standard membrane cleaning protocols and
reloading fresh enzyme catalyst.
Very high catalyst activity was achieved by immobilizing lipase
onto porous fluoropolymer support, and the enzymatic activity was
maintained for multiple reuses. In addition, the enzyme catalyst
could be removed from the membrane surface with detergent treatment and the membrane could be reloaded with fresh catalyst with
no loss in catalytic activity. Some advantages of our process, Eastman
GEM™ technology are described in more detail below.
The use of enzymes as catalysts to produce cosmetic esters has
been investigated by several academic groups and a few commercial
enterprises. Figure 2 illustrates one way to incorporate an enzyme
catalyst into common manufacturing equipment, such as a stirred
tank. The enzyme is bound to a solid support, then the immobilized
catalyst is added to the reaction mix and agitated to maximize contact with the reactants. The by-product, typically water for a condensation reaction, is removed to drive the reaction to completion. The
catalyst, enzyme immobilized on a support particle, is filtered from
the reaction. If the reaction product is of high enough purity, the
filtered product can be packaged directly from the reactor.
Reuse of an immobilized enzyme catalyst
A porous fluoropolymer membrane was loaded with an enzyme
catalyst and tested for activity in an esterification reaction to make
2-ethylhexyl palmitate. A lipase solution (Novozymes Lipozyme
CALB-L) was loaded onto a Millipore PVDF membrane using a pH 7
buffer to both bind the enzyme catalyst and wash the membrane 3).
After 24 hours, the excess enzyme solution was drained and the
membrane was rinsed twice with the phosphate buffer (pH 7). The
washed membranes were drained of excess fluid and stored damp at
4°C until the 2-ethylhexyl palmitate synthesis assay was performed.
For the 2-ethylhexyl palmitate synthesis assay, equimolar reactants
(palmitic acid and 2-ethylhexanol) were weighed separately in a reactor and melted at 65°C. The immobilized enzyme was added to the
reactants and the reaction was stirred at 60°C. The reaction was sampled after 6 to 24 hours depending on the experiment and the percent
conversion to the ester product (2-ethylhexyl palmitate) was estimated
by gas chromatography. The reactant and product peaks were integrated and the area percent of the product peak was recorded.
To investigate activity after sequential re-use of the immobilized
enzyme catalyst, the PVDF membrane was loaded with an enzyme
using the standard protocol, cut into small squares, then added to a
1 liter stirred tank reactor to catalyze the synthesis of 2-ethylhexyl
palmitate. The catalyst lifetime was compared to a reaction catalyzed
with the same enzyme immobilized on a polymer resin bead (Novozym 435). Figure 3 shows that after 59 sequential reuses, the enzyme
immobilized on resin beads began to lose activity. In contrast, no
activity loss was observed after over 100 sequential reuses of the
enzyme immobilized on the porous fluoropolymer.
Figure 2. Using an immobilized enzyme catalyst in a reactor
The enzyme support impacts catalytic performance
In enzyme-catalyzed reactions, immobilizing an enzyme catalyst
onto a solid support stabilizes the enzyme and prolongs its catalytic
lifetime. Immobilization also facilitates removal of the catalyst from
the reaction for reuse. In manufacturing applications, enzymes are
typically supported on polymer particles such as ion exchange
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Treatment group 1 in Table 1), though there was a small amount of
activity left on the stripped membrane. When the enzyme was
reloaded on the stripped membrane, the activity was not significantly different from the initial activity (Treatment group 3 vs Treatment group 1 in Table 1).
Figure 3: Enzyme catalyst reuse: resin beads vs porous fluoropolymer
We have demonstrated the ability to: bind an active enzyme to a
porous fluoropolymer support for use as a reaction catalyst, obtain a
consistent high rate of conversion over time, and strip inactive
enzyme catalyst from the membrane and rebind a fresh enzyme to
achieve the original conversion rate. Fluoropolymers are versatile
materials known for their excellent chemical resistance and ability
to tolerate a broad range of operating temperatures. The life of a
fluoropolymer membrane in an enzymatic or chemical process can
be very long, effectively reducing the cost of the catalyst support
over the lifetime of the process. The immobilization of enzymes on
membranes is a viable technology for the preparation of advantaged
enzyme-catalyzed processes.
Reuse of the polymer support material
Sustainability
One of the potential advantages of a membrane support and a
non-covalent enzyme interaction is the ability to strip inactive catalyst from the surface and rebind a fresh enzyme. This feature prolongs the useful life of the support material. To investigate reuse of
the enzyme support, the enzyme was immobilized on a PVDF
membrane as before, and the membrane was cut into 16 identical
strips and tested for catalytic activity in the 2-ethylhexyl palmitate
reaction and sampled after 24 hours (Treatment group 1 in Table 1).
Half of the membrane strips were then subjected to a treatment that
stripped the enzyme from the membrane (Treatment groups 2 and 3
in Table 1). The membrane was heated to 70°C in a two weight percent solution of DOW TRITON™ X-100 in water and stirred for 30
minutes. The stripping step was performed twice, then the stripped
membrane was washed twice with water at 70°C and twice at room
temperature to remove the surfactant. The membranes in treatment
group 3 were reloaded with a fresh enzyme catalyst according to the
standard protocol. The membrane reactors were then retested for
activity using the 2-ethylhexyl palmitate activity assay and a reaction
time of 24 hours.
The enzymatic synthesis of emollient esters has many benefits.
The reactions are driven to high conversion by removing the coproduct, usually water. The specificity of the enzymatic conversions and
the relatively low reaction temperatures increase yield, eliminate
processing steps, and minimize the formation of byproducts that
may contribute color or odor. The ester product is often pure enough
to obviate post-reaction processing. Eastman’s enzymatic process to
make esters, GEM™ technology, is environmentally advantaged over
conventional chemical esterification reactions. The benefits can be
measured in terms of reductions in energy and water use, greenhouse gas emissions and waste produced.
A simple comparison of the energy requirements and CO2 generation of a biocatalytic process to a conventional process route was
performed using Life Cycle Assessment calculation methods 4). The
scope of the analysis only includes the manufacturing process itself
and excludes upstream operations such as raw material production,
transport and handling, and downstream operations such as product
packaging, transport, and usage. This approach, often called a gateto-gate assessment, assumes the energy requirements and CO2
impact, outside of this narrowly defined scope, is essentially the
same regardless of the manufacturing process. The analysis focused
only on major energy steps or equipment such as steam heating,
agitators, and vacuum systems for a batch reactor system and indicated that Eastman’s GEM™ process to make 2-ethylhexyl palmitate
should reduce CO2 generation by 52% and energy consumption by
59%. See Figure 4.
The results in Table 1 show that upon detergent treatment, the
enzyme was stripped from the membrane (Treatment group 2 vs
Treatment
group
Description (number of replicates)
% conversion to ethylhexyl
palmitate at 60°C, after
24 hours Avg (std dev)
1
2
3
Experimental standards; initial use (n = 16)
Stripped membranes (n = 4)
Re-loaded with enzyme; ethanol pre-wet (n = 4)
73 (2.4) a
17 (1.5) b
71 (4.4) a
Today, there are only a few commercial cosmetic esters made
using an enzyme-catalyzed manufacturing process. But imagine
what would happen if all cosmetic esters used globally were made
using an enzyme-catalyzed process like Eastman GEM™ technology.
Table 1. Enzyme activity, measured as rate of 2-ethylhexyl palmitate formation, of
enzyme immobilized on porous PVDF membrane (Treatment group 1) after detergent stripping (Treatment group 2) and reimmobilizing fresh enzyme to the stripped membranes (Treatment group 3). Conversion rates at 24 hours, marked with
the same lower-case letter are not significantly different from each other.
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much more cost-effective. In addition, given the increasing demand
for sustainable consumer products, chemical manufacturers that
develop esters and other ingredients for personal care products have
a competitive advantage in the marketplace when they offer sustainable products. Eastman GEM™ technology offers a truly sustainable
solution for greener cosmetics through energy reductions and the
elimination of solvents and other wastes. While enzyme-catalyzed
processes for the production of green and natural ingredients is still
in its infancy, it holds great potential for the cosmetics industry
worldwide.
Formulations
The enzyme-catalyzed manufacturing process offers the advantage of producing materials with essentially zero impurities, which
is very important for ingredients used in personal care formulations.
One product made using Eastman GEM™ technology is 2-ethylhexyl
palmitate, which is a colorless, liquid emollient commonly used in
color cosmetics and skin care products as a solvent, carrying agent,
pigment wetting agent, or fragrance fixative.
Figure 4: Reductions made per batch by using Eastman GEM™ technology to product 2-ethylhexyl palmitate
Assuming proportional reductions in energy and water use and in
greenhouse gas production, then the benefit becomes socially substantial. See Table 2.
Measure
Savings Savings for all
for 1MT cosmetic esters Savings equivalent to 5)
(200,000 MT)
2-EHP
Greenhouse gas
(Kg CO2
61
equivalents)
Energy (BTU)
604,000
Water (Liters)
705
12.2 million
taking 2,773 cars off the road each year
121 billion
141 million
enough energy to heat 604 homes each year
drinking water for up to 193,150 people for a year
The following starting point formulations show how 2-ethylhexyl
palmitate can easily be formulated in color cosmetics and skin care
products.
Formulation 1:
Lip gloss formulation with Eastman GEM™ 2-ethylhexyl palmitate
Part Ingredient
Table 2. Using enzyme-catalyzed processes to make cosmetic esters can have a significant environmental benefit
A
Eastman GEM™
2-ethylhexyl palmitate
INCI name
Manufacturer or suggested
supplier
Wt.%
Ethylhexyl palmitate
Eastman Chemical Company
15.0
Sustainability is enhanced by using certified raw materials
Jojoba oil, organic
Simmondsia chinensis
(Jojoba) seed oil
The Jojoba Company
5.0
Recently, Eastman added a Roundtable on Sustainable Palm Oil
(RSPO) certified variation of GEM™ 2-ethylhexyl palmitate to its
product portfolio. Palm oil and its derivatives are used in food, personal care, biofuel, and industrial applications. Palm oil is a biobased, renewable, raw material produced from palm fruits grown on
plantations in tropical climates, but not all palm plantations are
managed sustainably. The RSPO is a non-profit association helping to
implement global standards for sustainable palm oil. Today, about
20% of the world’s palm oil has been certified as sustainably produced by the RSPO 6). When manufacturers choose RSPO-certified
palm oil for their manufacturing processes, they help bring more
green options to the consumer.
Color mica
Mica
Impact Colors, Inc.
3.0
Eastman Sustane™ SAIB
sucrose acetate
isobutyrate
Eastman Chemical Company
15.0
Foral™ 85 E CG
hydrogenated rosinate
Glyceryl hydrogenated
rosinate
Eastman Chemical Company
15.0
Shea butter, organic
Butyrospermum parkii
(shea) butter
The Organic Shea Butter
Company
5.0
Candelilla wax
Euphorbia carifera
(candelilla) wax
Majestic Mountain Sage Inc.
4.0
D
Polyisobutene 1200
Polyisobutene
MakingCosmetics Inc.
37.5
E
Vitamin E
Tocopherol
Sigma-Adrich Co. LLC
0.5
B
C
Procedure:
1. 1. Premix part A components at room temperature to ensure uniformity.
2. Set the temperature of a hot plate to 85°C.
3. Melt all ingredients in parts B and C in a separate beaker on the hotplate.
Blend the mixture by hand.
4. Stop heating. Add parts B and C to part A and mix.
5. Add part D to the mixture. Mix to have uniform color. Add E to the mixture.
Stir slowly to get rid of air bubbles.
6. Place the mixture in a plastic, lip gloss container.
Balancing the costs of green processing
Despite distinct advantages, there are still hurdles to the industrywide adoption of enzyme-catalyzed processes. As with many sustainability investments, enzyme-catalyzed processes have a higher initial
cost than traditional chemical reactions. However, the appropriate
choice of production conditions can spread this initial cost over a
large volume of product, making production using enzyme catalysts
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This formulation is easy to apply, goes on smooth, and gives lips
shine.
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Sources
Formulation 2:
Creamy facial cleanser formulation with sustainably produced Eastman GEM™
2-ethylhexyl palmitate
Part Ingredient
INCI name
Manufacturer or suggested
supplier
Wt.%
1) Source: Landor Associates Green Brands surveys, 2010-2012 (1). (2,)
http://hubmagazine.com/html/2013/hub_53/mar_apr/237230313/landor_
accountability/index.html
http://landor.com/#!/talk/articles-publications/articles/green-brands2012-four-insights-into-consumer-eco-perceptions/
A
Water
Aqua
DI water from filter
70.2
B
Eastman GEM
2-ethylhexyl palmitate
Ethylhexyl palmitate
Eastman Chemical Company
10.0
Glycerin
Glycerin
MP Biomedicals, LLC
4.0
4) US Patent 6,635,775
Cetyl alcohol
Cetyl alcohol
Sigma-Aldrich Co. LLC
5.0
Jojoba oil, organic
Simmondsia chinensis
(jojoba) seed oil
The Jojoba Company
5.0
Emulse™ 165
Glyceryl stearate (and)
PEG-100 stearate
Essential Ingredients, Inc.
5.0
5) 1 car = 500 gallons gasoline/year = 4,400 Kg CO2 eq. (1 gallon gasoline = 8.8
Kg CO2 eq.)
1 Home = 12.000 kWh/year = 200 million BTU
http://www.energy.ca.gov/commissioners/rosenfeld_docs/Equivalence-Matrix_2001-05.pdf
Minimum of 2 Liters/ day for adequate intake
Carbopol® Ultrez 10
Carbomer
The Lubrizol Corporation
0.3
Sodium hydroxide, 20%
Sodium hydroxide
Sigma-Aldrich Co. LLC
0.5
D
Caprylyl glycol EHG
Caprylyl glycol (and)
ethylhexylglycerin
Thor Personal Care SAS
0.0
E
Fragrance
Fragrance
The White Barn Candle Co.
C
2) BCC Research, Global Markets for Chemicals for Cosmetics & Toiletries, Chapter 4 Table 1
3) See US Patent 8,889,373 for procedural details
6) http://www.rspo.org/consumers/about-sustainable-palm-oil
polymer
5 drops
Procedure:
1. Set the temperature of a hot plate to 50°C.
2. Heat water in a beaker on the hot plate.
3. Melt/mix all ingredients in part B in a separate beaker on the hot plate.
Blend the mixture by hand.
4. Add part B to part A under 500 rpm.
5. Stop heating. Add part C to the mixture of parts A and B while stirring.
6. Cool to room temperature while stirring. Add parts D and E to the mixture.
7. Continue stirring for another 10 minutes.
This creamy, soap free, facial cleanser provides moisture to the
skin after washing.
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Stephanie Clendennen,
Jinghua Yuan,
Senior Technology Associate,
Principal Technical Service Representative,
Eastman Chemical Company
Eastman Chemical Company
[email protected]
[email protected]
EURO COSMETICS
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