Daily Cosmetic Research Analysis
Three studies advance sustainable and safety-conscious cosmetic science: an open-source, solar-powered chromatography–bioassay platform for non-target safety analysis of cosmetics; a microfluidic-ultrasonic route to generate surfactant-free emulsions; and a human study quantifying water use when rinsing shampoos/conditioners by hair characteristics. Collectively, they point to greener product development and more objective, field-deployable testing.
Summary
Three studies advance sustainable and safety-conscious cosmetic science: an open-source, solar-powered chromatography–bioassay platform for non-target safety analysis of cosmetics; a microfluidic-ultrasonic route to generate surfactant-free emulsions; and a human study quantifying water use when rinsing shampoos/conditioners by hair characteristics. Collectively, they point to greener product development and more objective, field-deployable testing.
Research Themes
- Sustainable, open-source analytical platforms for cosmetic safety
- Surfactant-free emulsion engineering via microfluidics and ultrasound
- Water footprint and rinsability metrics for hair care products
Selected Articles
1. Consolidating two laboratories into the most sustainable lab of the future: 2LabsToGo-Eco.
An upgraded, open‑source chromatography–bioassay system (2LabsToGo‑Eco) integrates 12 new elements, including solar power and automated sampling, to enable quantitative non‑target safety analysis. It drastically reduces cost, space, weight, and power demands and was demonstrated on cosmetics, personal care products, and foods.
Impact: This platform democratizes high‑throughput, non‑target safety screening of cosmetics with orders‑of‑magnitude lower resource needs, supporting greener regulatory and industrial workflows.
Clinical Implications: While not a clinical tool, faster non‑target safety screening can reduce consumer exposure to hazardous compounds in cosmetics/personal care products and support public health decisions.
Key Findings
- Introduces 12 new features (solar panels, autosampler, Mini‑Shaker, Nebulizer, Mini‑Incubator, enhanced imaging, electronic mainboard) in an open‑source system
- Reduces instrument investment cost ×35, starting capital ×18, weight ×12, infrastructure/bench space ×9, and power ×4 (×711 with solar)
- Demonstrated quantitative non‑target safety analysis for cosmetics, personal care products, and foods
- Enables mobile, on‑site testing and customization to prioritize hazardous unknowns
Methodological Strengths
- System-level engineering with quantified reductions in cost, footprint, and power
- Open-source design enabling reproducibility and broad adoption; demonstrated use on real product classes
Limitations
- Performance metrics (limits of detection, accuracy across diverse matrices) are not comprehensively detailed
- Field validation scope and sample numbers for cosmetic testing are not specified
Future Directions: Standardize analytical validation for regulatory acceptance, expand bioassay panels, and conduct multi-site field studies benchmarking against conventional labs.
BACKGROUND: The miniaturized 2LabsToGo predecessor system consolidated most devices used in the planar chromatography laboratory and toxicological bioassay testing laboratory; however, important features for greater user convenience were still missing. It can be used for non-target chemical safety analysis of products on the global market or environmental samples to detect known and unknown hazardous compounds. RESULTS: The system had to be redeveloped due to the many changes and improvements and was termed 2LabsToGo-Eco to make this difference recognizable. Twelve new key elements were implemented for the first time, such as solar panels for power supply-free operation, autosampler for hands-free application of samples, Mini-Shaker, Nebulizer, and Mini-Incubator as smart bioassay tools, superior tools for imaging, and electronic mainboard to eliminate cable and circuit board clutter. It was again designed open-source for do-it-yourself assembly. Miniaturization and dematerialization let to the reduction (compared to the status quo) of instrument investment costs by a factor of 35, starting capital by a factor of 18, weight by a factor of 12, infrastructure and bench space requirement by a factor of 9, and power supply by a factor of 4 or even 711 using solar energy. The new 2LabsToGo-Eco was proven and demonstrated for quantitative non-target safety analysis of cosmetics, personal care products, and foods. SIGNIFICANCE: For the first time, the sustainable 2LabsToGo-Eco is ready to go viral to allow for a non-target safety analysis with a prioritization strategy using the consolidated chromatography-bioassay lab. It boosts the transformation of laboratories towards sustainability, enables mobile on-site testing, allows customization of instruments, and democratizes access to chromatography and bioassay equipment.
2. Oil-in-water segmented flow in the optimized microfluidic system for surfactant-free ultrasonic emulsification.
A microfluidic pre‑processing device that uses a needle‑inserted glass capillary generates stable oil droplets without surfactants and, when coupled with ultrasonic emulsification, improves processing efficiency. This provides a precise and sustainable route to formulate emulsions for cosmetics and related fields.
Impact: Surfactant‑free emulsification directly addresses irritation/toxicity and environmental concerns in topical formulations, enabling greener cosmetic product development.
Clinical Implications: Although preclinical, surfactant‑free droplet generation may reduce skin irritation potential of topical products and support cleaner excipient profiles in dermatologic and cosmetic formulations.
Key Findings
- Needle‑inserted glass capillary channels produced stable oil droplets by increasing water affinity and minimizing oil–wall contact
- High‑speed imaging and image analysis quantified oil–water segmentation across three channel designs
- Pre‑fragmented droplets enhanced ultrasonic emulsification efficiency, offering a surfactant‑free alternative
Methodological Strengths
- Comparative evaluation of three microchannel architectures with quantitative imaging
- Integration with ultrasound demonstrates end‑to‑end feasibility for practical emulsification
Limitations
- Shelf‑life and droplet size distribution of final emulsions were not comprehensively reported
- No head‑to‑head comparison against standard surfactant‑based cosmetic formulations
Future Directions: Scale-up, integration into continuous manufacturing, and validation with real cosmetic actives/excipients, including safety and stability testing.
Droplet-based microfluidics is a promising technique for generating stable emulsions in various applications, including pharmaceuticals, food, cosmetics, and biosensors. However, conventional methods rely on surfactants, which pose potential toxicity and environmental concerns. To address this issue, we developed a microfluidic device for surfactant-free oil droplet generation, serving as a pre-processing stage for ultrasonic emulsification. Three microfluidic channels were designed: a conventional T-junction, a needle-inserted channel, and a needle-inserted glass capillary channel. Oil-water flow segmentation characteristics of the fabricated devices were analyzed using high-speed camera and image processing techniques. Results demonstrated that the needle-inserted glass capillary exhibited superior stability, effectively generating oil droplets rather than slugs by utilizing a higher water affinity and minimizing oil contact with the channel walls. Furthermore, when integrated with ultrasonic emulsification, the pre-fragmented oil droplets exhibited improved processing efficiency. These findings highlight the potential of combining microfluidic pre-processing with ultrasound emulsification as a viable alternative to surfactant-based methods, offering enhanced precision and sustainability in droplet generation and emulsion formation.
3. Understanding the water consumption associated with the use of hair care products: The impact of six hair characteristics on rinsing shampoos and conditioners.
In a 4‑month salon‑based study of 148 women, rinsing required on average 7.1 L for shampoos and 6.3 L for conditioners. Hair length and abundance increased water use, while thickness, curliness, dryness, and damage showed no significant effect, supporting rinsability as a key metric for product water footprints.
Impact: Provides a scalable methodology and benchmark data to quantify water use in the use phase of hair care products, informing eco‑design and consumer guidance.
Clinical Implications: May inform dermatologists’ counseling on sustainable hair care practices and guide development of low‑rinse formulations that reduce water use without compromising cleansing.
Key Findings
- Average water use: 7.1 L to rinse shampoos and 6.3 L for conditioners
- Hair length and abundance significantly increase rinsing water requirements
- Hair thickness, curliness, dryness, and damage do not significantly affect water use under the test conditions
- Trained hairdressers used dual endpoints (visual disappearance and clean touch) to standardize rinsing end‑point
Methodological Strengths
- Prospective, salon‑based testing with standardized pre‑wash and trained assessors
- Evaluation across six hair characteristics and 20 sessions over 4 months
Limitations
- Female participants only and a limited set of 10 shampoos/10 conditioners
- Potential assessor bias; results may vary with water pressure/temperature and geography
Future Directions: Validate across broader demographics and product types, include objective flow metering, and test low‑rinse formulations under varied water conditions.
OBJECTIVE: Environmental life cycle assessment of hair care products shows that the highest environmental impact is associated with the use phase, rather than conception, production, packaging, distribution or disposal of the products themselves. To measure the water consumed in the use phase, an innovative and cost-effective methodology was developed and tested to measure the water consumed to rinse off hair care products (rinsability). METHODS: Over 4 months, we tested the rinsability of 10 shampoos and 10 hair conditioners applied to 148 females, split between six hair characteristics: length, volume, dryness, thickness, curliness and damage. The volunteers were received in a hair salon on 20 different occasions for about 30 min each time. A team of hairdressers was specifically trained to detect two indicators of when a product is rinsed: a visual disappearance of the product and a clean touch. The volunteers were asked to have their hair washed at home 48 h before their arrival, using a standardized shampoo to control for sebum apparition. RESULTS: According to this test, on average, 7.1 L of water are needed to rinse a shampoo and 6.3 L to rinse a hair conditioner. However, there are significant differences depending on hair types: long and abundant hair requires more water to rinse shampoos and conditioners, whereas hair thickness, curliness, dryness and damage do not significantly affect the water required. CONCLUSION: We suggest that data on product rinsability are essential when considering the water footprint for shampoos and hair conditioners. This method could be adopted for industry-wide experimentation to assess the water footprint of products and set reduction targets. OBJECTIF: L'évaluation du cycle de vie environnemental des produits de soins capillaires montre que l'impact environnemental le plus élevé est. associé à la phase d'utilisation plutôt qu'à la conception, la production, l'emballage, la distribution ou l'élimination des produits eux‐mêmes. Pour mesurer l'eau consommée pendant la phase d'utilisation, une méthodologie innovante et rentable a été développée et testée afin de mesurer l'eau consommée pour rincer les produits de soins capillaires (rinçabilité). MÉTHODES: Pendant quatre mois, nous avons testé la rinçabilité de dix shampooings et dix après‐shampooings appliqués chez 148 femmes, réparties selon six caractéristiques de cheveux: longueur, volume, épaisseur, degré de sécheresse et de frisure, et dommages. Les volontaires ont été reçues dans un salon de coiffure à 20 occasions différentes, pendant environ 30 min à chaque fois. Une équipe de coiffeurs a été spécialement formée pour détecter deux indicateurs de rinçage d'un produit: une disparition visuelle du produit et un toucher propre. Les volontaires ont été invitées à se laver les cheveux à domicile 48 heures avant leur arrivée en utilisant un shampooing standardisé afin de contrôler l'apparition de sébum. RÉSULTATS: Selon ce test, en moyenne 7,1 litres d'eau sont nécessaires pour rincer un shampooing et 6,3 litres pour rincer un après‐shampooing. Cependant, des différences significatives existent en fonction des types de cheveux: les cheveux longs et abondants nécessitent plus d'eau pour rincer les shampooings et après‐shampooings, tandis que l'épaisseur des cheveux, le degré de frisure et de sécheresse, et les dommages n'affectent pas significativement la quantité d'eau nécessaire. CONCLUSION: Nous suggérons que les données sur la rinçabilité des produits sont essentielles dans la prise en compte de l'empreinte environnementale des shampooings et après‐shampooings en termes d'eau. Cette méthode pourrait être adoptée lors des expérimentations à l'échelle de l'industrie afin d'évaluer l'empreinte environnementale des produits et de fixer des objectifs de réduction.