In the growing movement to tackle the environmental impact of consumer products, reusable packaging has emerged as a promising solution. But is it always the most eco-friendly option? We performed a study using CarbonBright’s AI-driven Life Cycle Assessment (LCA) software to find that the answer is more nuanced than you might expect.

Understanding the Carbon Footprint: Plastic vs. Aluminum

To examine this, we analyzed two packaging scenarios for a 500 ml bottle of shampoo: one using a single-use plastic bottle made of 50% recycled content, and the other involving a reusable aluminum bottle also made from 50% recycled content.

Figure 1: Life cycle emissions of shampoo in a single-use plastic bottle (50% recycled content)
Figure 2: Life cycle emissions of shampoo in a reusable aluminum bottle (50% recycled content)

At first glance, the results are surprising: the shampoo in the plastic bottle generated 1.25 kg CO2e, while the shampoo in the aluminum bottle produced over three times that amount—1.56 kg CO2e. Why would an environmentally-conscious option like reusable aluminum generate more emissions than plastic?

The catch, of course, is that aluminum bottles are designed for repeated use, whereas plastic bottles are typically discarded after a single use. So, we then factored in the reusability of the aluminum bottle.

Concentrates: Shampoo in a New Form

To maximize the environmental benefit of reusable packaging, we paired the aluminum bottle with a shampoo concentrate. Rather than buying a new 500 ml bottle of shampoo each time, consumers would simply refill the aluminum bottle using the concentrate and water. The concentrate, packaging made from plastic but with 0% recycled content, produced just 1.01 kg CO2e compared to 1.25 kg CO2e produced from the single-use plastic bottle shampoo.

This means that with every refill using shampoo concentrate, consumers dramatically reduce their carbon footprint compared to continuously purchasing new 500ml plastic bottles.

Figure 3: Life cycle emissions of a shampoo concentrate in a single-use plastic bottle (0% Recycled Content)

When Reuse Beats Single Use: The 3-Refill Threshold

The question then becomes: when does this reusable system actually become more eco-friendly than the single-use plastic option? According to our study, the environmental “break-even” point occurs after purchasing three bottles of shampoo concentrate while reusing the aluminum bottle. Once a consumer reaches this point, the reuse scenario begins to generate fewer emissions than the single-use alternative. Every additional refill beyond that point continues to save CO2e emissions and cut down on waste.

Figure 4: Impact of shampoo in single-use plastic bottles compared to a reuse scenario with a reusable aluminum bottle and shampoo concentrate in a single-use plastic bottle.

Plastic vs. Aluminum: Beyond Carbon Emissions

But the story doesn’t end with carbon emissions. While plastic may initially seem like a more efficient option in terms of CO2e, it has severe environmental downsides. Plastic waste remains in the environment indefinitely, breaking down into microplastics that harm wildlife and pollute ecosystems. Worse still, plastic recycling rates remain abysmally low—just 8.7% in the U.S. as of 2018.

Aluminum, on the other hand, boasts a much higher recycling rate of 34.9%, and unlike plastic, it can be recycled indefinitely without losing its quality. Aluminum, being a naturally occurring element, doesn’t persist in the environment as a toxic pollutant, even though it does take a long time to decompose.

The Verdict: A Balanced Approach

So, is reusable packaging better for the environment? Like many things in sustainability, it depends on the context and consumer behavior. If you’re only using a reusable aluminum bottle once or twice before switching back to plastic, then the single-use plastic bottle may indeed result in lower emissions. However, if you commit to long-term use and leverage refill systems, the environmental benefits of reusables become clear—especially when considering factors beyond carbon, such as the full life cycle of materials and their environmental persistence.

Want to Take It a Step Further?

What if there was a solution that outperforms both single-use and reusable packaging right from the start? It might sound groundbreaking—but it’s actually an age-old practice: a simple bar of soap. In fact, this concept has been reimagined as the modern shampoo bar. Although liquid shampoo feels like a staple, it’s a relatively recent invention, created by German chemist Hans Schwarzkopf in 1927.

Shampoo bars, on the other hand, require little to no packaging. In our study, a shampoo bar using a cardboard box made with 0% recycled content generated just 0.25 kg CO2e—the lowest emissions of any option we tested. 

Table 1: Total life cycle emissions and life cycle emissions per use of shampoo in various packaging.

ProductTotal Emissions (kg/CO2e)Uses Per ProductEmissions per Use (kg/CO2e)
Plastic Bottle (50%)1.2501500.0250020
Aluminum Bottle (50%)1.5571500.0311420
Concentrate – Plastic Bottle (0%)1.0082500.0201640
Shampoo Bar – Cardboard Box0.2532600.0042200
Figure 5: Life cycle impact by stage of shampoo in a single-use plastic bottle (50% recycled content) (Left) compared to a shampoo bar in a cardboard box (0% recycled content) (Right). 

There are even more sustainable alternatives, such as cardboard or paper with recycled content, or going completely package-free. In addition to their minimal environmental impact, shampoo bars often last longer (60-80 uses per bar), save space, and are a cost-effective solution while delivering the same luxurious results. Beloved by travelers (no liquid restrictions for TSA!) and eco-conscious consumers alike, shampoo bars are the ultimate low-impact option.

How Does Less Packaging Benefit My Company?

Boost Stakeholder Interest: Reducing your reliance on raw materials not only strengthens your company’s resilience against natural disasters and supply chain disruptions but also demonstrates proactive environmental stewardship—something today’s stakeholders increasingly prioritize.

Cut Costs on Operations and Materials: Streamlining your packaging—or eliminating it altogether—can lead to substantial cost savings. Packaging forms that are more compact and lighter in weight leads to reduced transportation and storage costs per unit. Using recycled materials also reduces your reliance on raw resources, and often comes with lower energy requirements for production.

Achieve Environmental Goals: As consumer demand for sustainable products continues to grow, offering environmentally friendly solutions helps your company align with the values of both customers and investors. Plus, you’ll be actively contributing to a healthier planet—a win for everyone involved.

Key Takeaways

A reuse scenario, combined with smart innovations like shampoo concentrate, can greatly reduce environmental impact—but only with long-term consumer commitment. It’s not just about choosing the right bottle; it’s about adopting sustainable habits that create lasting change. For companies looking to cut their packaging footprint even further without compromise, solutions like shampoo bars offer a simple and effective way to eliminate primary packaging costs entirely.

* The Life Cycle Assessments (LCAs) were performed using CarbonBright’s AI-driven software, utilizing standard ingredient formulations and packaging specifications for each shampoo solution.


At CarbonBright, we believe in your potential to make a difference. We specialize in developing innovative solutions that enable organizations to conduct Life Cycle Assessments (LCAs), quantify their emissions, and meet stringent regulatory requirements. By partnering with CarbonBright, organizations can achieve a more efficient and cost-effective solution compared to traditional methods. Our scientifically-based approach, aligned with industry standards, ensures accurate and credible results that support your journey towards sustainability and compliance with emerging climate action standards.

Contact us to learn more about how we can help you accelerate your sustainability journey and meet the complex requirements of Life Cycle Assessments (LCAs).