Hands-on Activity Make It Clean!
Engineering a Multipurpose Cleaning Product

Learning Objectives

After this activity, students should be able to:

• Describe green chemistry and sustainability principles.
• Demonstrate hands-on skills in product development, testing, and problem solving.
• Practice teamwork, creativity, and communication by presenting the project and working collaboratively.

Educational Standards

Each Teach Engineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in Teach Engineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

Common Core State Standards - Math

International Technology and Engineering Educators Association - Technology

Materials List

Each group needs:

• (optional) laptop/tablet with internet access (for research)
• 1 Informational Sheets packet
• 1 bottle of water (17 fl. oz or smaller)
• 100 mL graduated cylinder (to measure water, vinegar, and alcohol)
• 100 mL vinegar
• 100 mL isopropyl alcohol (60-70%)
• 2 100 mL plastic bottles with caps
• 1 teaspoon
• 10 tsp baking soda (sodium bicarbonate)
• 10 tsp citric acid
• 2 small paper envelopes or bags (similar to this product: https://www.amazon.com/ESSENTIAL-Envelopes-Gummed-Envelope-Office/dp/B09X194G5G)
• 4-6 250 mL plastic cups or beakers (for mixing mixtures)
• 1 glass stir stick or metal spoon (reusable option) or 3-5 wooden stir sticks (disposable option)
• 1 mL of an essential oil (e.g., orange, lemongrass, rosemary, lavender)
• 1 Eppendorf vial (similar to this product: https://www.amazon.com/Microcentrifuge-Sterilized-Plastic-Storage-Without/dp/B0BBV68SZT)
• paper towels
• 1 white plastic plate (reusable option) or 3-5 white paper plates (disposable option)
• 1 spray bottle (clean and empty)
• 2 adhesive labels

Each student needs:

• 1 Activity Worksheet
• 1 lab coat/apron
• 1 pair of safety glasses (goggles)
• 1 pair of latex-free disposable gloves

For the class to share:

• 1 laptop/tablet with projector to show the Make It Clean Presentation
• 1 bottle of ketchup (or another safe stain substance)
• various colored markers

Worksheets and Attachments

Pre-Req Knowledge

Students should be familiar with metric units.

Introduction/Motivation

(Prepare and project the Make It Clean Presentation for the class to view.)

Today, you are not just students: You are product designers, chemists, and problem solvers. You have been hired by a community co-op that wants to stop using harsh chemical cleaners in homes, schools, and small businesses. They are counting on you to research and design a powerful, safe, and eco-friendly cleaning product.

But before we start designing, let’s think about why this matters. (Display Slide 2 of the Make It Clean Presentation.) Why do we have to take care of water? (Let students offer answers.) Water is one of the most important resources on Earth. We drink it, cook with it, wash with it, and grow food with it, and ecosystems depend on it.

We know water is essential, but unfortunately human activities can pollute it. How do we pollute water every day? (Let students offer answers. Potential answers include plastics, oil, chemicals from factories and homes. Try to drive the answers toward cleaning supplies.) Those are great answers. What about everyday cleaning, like washing our hands or cleaning the counter? Every time we wash our hands, rinse dishes, or wipe down a counter, that water doesn’t just disappear. It travels through drains, pipes, and treatment systems and eventually returns to rivers, lakes, groundwater, and oceans.

That means whatever goes down the drain can end up in the environment. (Display Slide 3.)  Many traditional cleaning products contain chemicals such as ammonia, chlorine bleach, synthetic fragrances, and phosphates. (Display Slide 4.) These ingredients can cause problems such as:

• Polluting rivers and lakes.
• Harming fish and aquatic life.
• Contributing to algae blooms that remove oxygen from water.
• Irritating human skin, lungs, and eyes.
• Triggering asthma or allergies for some people.

Engineers and chemists are working to solve this problem by designing cleaners that work well but are safer for people and the planet. Today, you will take on that challenge. How can we avoid water pollution?  (Let students offer answers.)

(Display Slide 5.) Let’s start by thinking about this: What do you use to clean at home? What do you smell when someone sprays a cleaner on the counter? Have you ever gotten a headache, itchy eyes, or a cough after cleaning? Or even just walking into a room that was just cleaned?

Take 30 seconds. Turn to your neighbor and share one cleaning product you’ve seen or used, and how it made you feel—good, bad, or in-between. (Give time for discussion. Walk around and listen to student responses.)

Now let’s bring it back. What did you hear? Did anyone say that the cleaner smelled too strong or caused discomfort? Did anyone mention using homemade products, like vinegar and baking soda? (Take 1–2 student responses.) This is what real science and engineering is about, asking questions that matter to our lives and our communities.

(Display Slide 6.) Today you are going to investigate:

• What makes a cleaner work?
• Can natural ingredients clean just as well as chemicals?
• What’s the impact of those ingredients on our health and the planet?
• How can we design something that is good for both people and the environment?

We will explore natural ingredients such as vinegar, baking soda, and essential oils. You will test how well your products clean real messes. Then, you will design packaging that’s beautiful, biodegradable, and minimal-waste.

(Display Slide 7.) But we are not stopping at the science; you will also brand your product: create a name, logo, and label that explains why your cleaner is safe and effective.

Let’s start by generating some big questions together. I want you to think about your real life, your home, your community, and your environment.

Ask yourself:

• What kinds of cleaners are most used where I live?
• What concerns do people in my home have about cleaning products?
• Do I know anyone who has allergies or asthma?
• What ingredients do I recognize or not recognize on labels?

Let’s take a moment to write down one question or concern you have about cleaners, anything from health to the environment to how to get a stain off your sneakers. This will guide your research and help your team choose a product that really matters. (Let students write for a minute or two. Then invite a few to share.)

Procedure

Background

Water pollution is a major environmental issue worldwide and affects both ecosystems and human health. Many sources contribute to water pollution, including industrial waste, agricultural runoff, plastics, and chemicals used in homes and businesses. Everyday products such as cleaning supplies, detergents, and disinfectants can contain chemicals that enter waterways when they are rinsed down drains. Even though wastewater treatment plants remove many contaminants, some chemicals can still pass through treatment systems and eventually reach rivers, lakes, and oceans. These substances may harm aquatic organisms, contribute to problems such as harmful algal blooms, and disrupt natural ecosystems. As a result, there is growing global awareness of how the products people use in daily life can affect water quality and environmental sustainability.

In response to these concerns, scientists and engineers are increasingly focused on developing cleaning products that are effective while also being safer for people and the environment. This approach is often connected to the principles of green chemistry, which encourage the design of products and processes that reduce or eliminate hazardous substances. Many eco-friendly cleaners use naturally derived ingredients such as vinegar, citric acid, or baking soda to break down grease, remove stains, or neutralize odors. These alternatives can reduce the environmental impact of household cleaning while still performing essential functions.

In this activity, the ingredients provided to students are safe for classroom use. However, like many substances used in chemistry, their properties can change when two or more materials are combined. For example, mixing certain ingredients can alter acidity, create reactions that release gas, or change the cleaning effectiveness of the solution. It is important that students carefully read the informational materials provided and consider the properties of each ingredient before designing their cleaner. By researching ingredients and making thoughtful decisions about mixtures, students practice the type of investigation and problem solving that engineers and chemists use when developing safer consumer products.

Before the Activity

• Make copies of the:
• Activity Worksheet (1 per student).
• Informational Sheets (1 per group).
• Gather and prepare materials
• Measure and put 100 mL vinegar into a 100 mL bottle with cap (1 per group).
• Measure and put 100 mL isopropyl alcohol into a 100 mL bottle with cap (1 per group).
• Measure out 10 tsp baking soda and put into the paper envelope or bag (1 per group).
• Measure out 10 tsp citric acid and put into the paper envelope or bag (1 per group).
• Measure 1 mL of an essential oil) into 1 Eppendorf vial (1 per group).
• (optional) You can offer the students more than one essential oil; dose them into 1mL Eppendorf vials.

During the Activity

Ask (~10 minutes)

1. Divide the students into groups of 2–3.
2. Optional: Review laboratory safety expectations, emphasizing safe handling of all ingredients and proper cleanup procedures.
3. Have students put on protective equipment, including goggles, gloves, and lab coats or aprons.
4. Optional: Review the steps of the engineering design process.
5. Distribute one Activity Worksheet to each student.
6. Present the design challenge and time constraints:

• Design, create, and test an eco-friendly, nontoxic cleaning product that effectively cleans surfaces while being safe for people and the environment.
• Remind students that this is a timed engineering design challenge, organized into research, planning, testing, and product development phases.

Research (~20 minutes)

7. Optional: Give students time to use the internet to research the principles of green chemistry and the harmful effects of traditional chemical-based cleaners.
8. Step 1: Understand and Test Materials

• Provide each group with the Informational Sheets packet.
• Allow students to read the informational sheets and discuss:
• Environmental and health impacts of traditional cleaners.
• Properties of natural cleaning ingredients such as baking soda, vinegar, citric acid, and essential oils.
• Instruct students to complete Step 1 of their Activity Worksheet based on the Informational Sheets packet.

9. Step 2: Experiment with Mixtures

• Have each group collect the materials for Step 2 of their Activity Worksheet.
• Remind students to handle all materials responsibly and return unused supplies.
• Give each group time to complete Step 2 and record their observations.

10. Conduct an activity checkpoint:

• When finished with Steps 1 and 2 of the Activity Worksheet, have each group raise their hand or come to the front of the classroom to be checked.
• If each team member has correctly completed Steps 1 and 2, allow the students to move on to Part 3.
• If one or more group members have not yet completed their Steps 1 and 2, send the group back to finish.

Imagine and Plan (~10 minutes)

11. Encourage teams to identify which ingredients may be most effective for their intended type of cleaner (e.g., all-purpose, glass, bathroom).

12. Instruct students to brainstorm and plan their cleaning solution in Step 3 of their worksheet. Teams should:

• Decide on the type of cleaner they will design.
• Select natural, nontoxic ingredients based on their research.
• Predict how their formula will work and justify their ingredient choices.

13. Direct students to document their initial plan and rationale on the Activity Worksheet in Step 3.

Create and Test (~20 minutes)

14. Have each group collect materials for their product, including measuring tools, ingredients, and cups.
15. Remind students to handle all materials responsibly and return unused supplies.
16. Direct each group to use one cup to test their chosen formulation.
17. Give students 10 minutes to complete Step 4:

• Mix small test batches.
• Evaluate cleaning effectiveness by removing stains or residue from a test surface (e.g., ketchup on trays or plates). Note: To record the cleaning power of the cleaning mixtures, provide a disposable plate or a white plastic plate and smear ketchup on it. Students can test how effective the mixtures are in removing the stains from the plate. Reference the following Cleaning Power Reference Chart:

  4	Completely Clean (No ketchup left)
  3	Mostly Clean (Very small smudges left)
  2	Somewhat Clean (Visible streaks/spots remain)
  1	Barely Clean (A lot of ketchup still there)
  0	No Change (Looks the same as before cleaning)

• Observe results such as stain removal, scent, residue, and ease of use.
• Have students reflect on their results by answering the questions in Step 4.

(Optional; if time allows) Improve

18. Based on their results, have each group decide how to improve their product in Step 5.
19. Monitor groups as they test, revise, and improve their formulas. Encourage teams to:

• Record observations and results in their worksheets.
• Adjust ingredient ratios to improve performance.
• Justify any design changes based on test data.
• Provide additional ingredients if needed and support student troubleshooting.

Final Product Marketing and Documentation (~30 minutes)

20. Once each group has a formula they think works, have them work through Step 6 of the Activity Worksheet to test their final cleaner on their worktable surface, or you may provide trays or plates with ketchup to ensure consistent testing conditions. Students should evaluate:

• Cleaning ability.
• Scent.
• Residue.
• Ease of application.

21. Once teams finalize their formulation, instruct them to name their product and record the final recipe with its costs in Step 7 on their Activity Worksheet.
22. Have each group then prepare a full batch in the spray bottle, labeling it temporarily with their group name and cleaner type.
23. Instruct students to start Step 8 and begin working on their product labels.

• Remind students to create a slogan.
• Provide white labels and markers.

24. Ask students to stop working and prepare their three-minute team presentations (Step 9). Each group should present:

• Their final formula and why they selected specific ingredients.
• How their product performed during testing.
• Why their cleaner is safe and environmentally friendly.
• Their packaging and branding strategy.

25. Encourage clear communication, teamwork, and creative marketing approaches.
26. Have each group give their presentation.
27. Have students individually answer the reflection questions in Step 10 of the worksheet.
28. Conclude the activity with a class discussion about the reflection questions.
29. Optional: Have teams write a report detailing their formulation process, the testing results, and their approach to sustainability.

Vocabulary/Definitions

acid: A substance that can donate a hydrogen ion (H⁺) in a chemical reaction; often has a sour taste (e.g., vinegar, lemon juice).

alkaline / base: A substance that can accept a hydrogen ion (H⁺) in a chemical reaction; often has a bitter taste and slippery feel (e.g., baking soda).

biodegradable: A material that can be broken down naturally by bacteria or other living organisms, returning to the environment safely.

chemical reaction: A process in which substances (reactants) change into new substances (products) with different properties.

citric acid: A natural acid found in citrus fruits; often used in cleaning to help remove stains and mineral deposits.

eco-friendly / green: Products or practices that are safe for the environment and reduce harm to people and nature.

environmental impact: The effect a substance, activity, or product has on the natural environment, including air, water, and soil.

essential oil: A concentrated plant extract that gives fragrance and sometimes cleaning properties; used in small amounts.

green chemistry: The design of chemical products and processes that reduce or eliminate hazardous substances.

innocuous: Causing no injury or damage.

mixture: A combination of two or more substances that are not chemically bonded and can usually be separated.

natural ingredient: A substance that comes from plants, minerals, or animals rather than being made synthetically.

nontoxic: Safe for humans and animals; does not cause harmful health effects under normal use.

pH: A scale (0–14) that measures how acidic or basic a substance is.

reaction rate: The speed at which a chemical reaction occurs; can be influenced by temperature, concentration, or mixing.

soluble: Susceptible of being dissolved in or as if in a liquid, especially water.

solution: A mixture in which one substance (solute) is completely dissolved in another (solvent), such as sugar in water.

toxicity: The degree to which a substance can harm humans, animals, or the environment.

volatile: A substance that easily evaporates at room temperature, sometimes giving off strong odors (e.g., alcohol).

waste reduction: Actions taken to minimize the amount of material thrown away, especially harmful chemicals.

Assessment

Pre-Activity Assessment

Probing Questions: Show the students the Make It Clean! Presentation. Introduce the topic of water pollution and the importance of taking care of water in the Introduction and Motivation section. Ask students questions like:

• Why do we have to take care of water? (Potential answers: Water is one of the most important resources on Earth. We drink it, cook with it, wash with it, and grow food with it, and ecosystems depend on it.)
• How do we pollute water every day? (Potential answers include plastics, oil, chemicals from factories and homes.)
• How can we avoid water pollution?  (Potential answers: Use eco-friendly or biodegradable cleaning products, reduce harmful chemicals in homes and businesses, properly dispose of chemicals instead of pouring them down drains, use natural cleaning ingredients, use smaller amounts of cleaning products, avoid dumping oil, paint, or chemicals into sinks or storm drains, recycle and properly dispose of plastics, reduce fertilizer and pesticide use, support environmentally friendly products and companies, educate others about protecting water systems.)

Wonder Question: Students write down one question or concern they have about cleaners, anything from health to the environment to how to get a stain off their sneakers. This will help guide student research and help students choose a product that really matters.

Activity Embedded (Formative) Assessment

Activity Checkpoint: Students pause to have pages 1 and 2 of their Activity Worksheet reviewed. Each group shows their work to you so you can quickly check for required elements using a short checklist. If the pages are complete, approve them and immediately hand over labels and markers. If something is missing, give a brief corrective prompt so students can make the fix and return for a quick second check. This process ensures that students stay on track and have all the necessary information before moving on to designing and labeling their product.

Observation of Teamwork and Investigation: As students work through testing and improving their formulas, circulate around the room and observe group discussions, testing procedures, and data recording. Look for evidence that students are applying scientific reasoning, collaborating with teammates, and adjusting their designs based on results.

Post-Activity (Summative) Assessment

Product Presentations: Each group presents their cleaning product. As they present, collect their completed worksheet. If you choose to evaluate the presentation, add brief notes directly on the worksheet. If not, simply review the completed worksheet as a summative assessment. You can use the Summative Assessment Rubric to assess the students.

Safety Issues

• Skin and eye irritation:
• Citric acid, baking soda, and vinegar can cause mild irritation.
• Require goggles and gloves at all times when handling ingredients.
• Have students wash hands immediately after the activity.
• Inhalation or sensitivity to fumes:
• Vinegar and essential oils produce odors that can irritate some students.
• Ensure good ventilation or open windows if indoors.
• Isopropyl alcohol hazards (if used):
• Highly flammable → keep away from heat or open flames.
• Do not let students ingest it.
• Have students handle in small, measured amounts, under your supervision.
• Mislabeling or accidental ingestion:
• Clearly label all spray bottles as “Do Not Drink / Cleaning Solution.”
• Emphasize that these are not for consumption.
• Slips and falls:
• Clean up any spilled liquids immediately.
• Keep floor areas around workstations dry.
• Allergies or sensitivities:
• Ask students ahead of time if they are sensitive to fragrances, vinegar, or essential oils.
• Have alternative stations or allow omission of essential oils for sensitive students.

Troubleshooting Tips

• Mixture doesn’t react as expected (e.g., fizzing, cleaning ability):
• Check ingredient ratios; too much water can dilute the reaction.
• Ensure that citric acid and baking soda are measured correctly so small amounts produce a noticeable reaction.
• Stir thoroughly; some ingredients may settle if not mixed well.
• Cleaner is too thick or too runny:
• Too thick → add small amounts of water gradually.
• Too runny → add more solid ingredient (baking soda or citric acid) carefully.
• Scent is too strong or weak:
• Adjust essential oil drops gradually; some oils are very concentrated.
• Remember: Less is safer, especially for students sensitive to fragrances.
• Stains not removed effectively:
• Ensure that the correct type of cleaner is being tested (all-purpose, glass, bathroom).
• Encourage students to adjust ingredient ratios based on observations.
• Test on the designated plate or tray; consistency matters for accurate evaluation.
• Messy or spilled mixtures:
• Use paper towels or spill trays immediately.
• Encourage students to clean up small spills as they occur to avoid cross-contamination.

Activity Extensions

Extensions (Deeper Learning Opportunities)

• User Testing
• Have students share their product with classmates or family members for feedback on its performance, scent, and ease of use. Record feedback to improve the final formula and design.
• Compare effectiveness:
• Have students compare their eco-cleaner against a small amount of a traditional chemical cleaner to measure performance differences.
• Quantitative analysis:
• Record data numerically and graph results (e.g., % of ketchup removed, scent rating, residue amount).
• Environmental impact study:
• Research environmental effects of the ingredients in traditional vs. natural cleaners.
• Discuss water pollution, biodegradability, and sustainability.
• Chemistry connections:
• Explore the chemical reaction between citric acid and baking soda.
• Investigate pH levels of mixtures and how acidity affects cleaning power.
• Engineering design iteration:
• Challenge students to design a “next-generation” cleaner based on test results.
• Encourage alternative formulations or packaging innovations.

Enrichment (For Advanced Students or Cross-Curricular Links)

• Marketing and business skills:
• Develop a full brand identity, including logo, slogan, and environmental messaging.
• Calculate the cost per batch of ingredients and discuss pricing strategy.
• STEM integration:
• Measure cleaning efficacy with more precise instruments (pH strips, conductivity meters, weight of removed residue).
• Use statistics to compare group results and determine “best formula” scientifically.
• Community impact project:
• Have students present their cleaner to another class, a school club, or a local community group.
• Discuss ways to implement eco-friendly cleaning in homes or businesses.
• Research extension:
• Investigate other natural cleaning agents (e.g., castile soap, hydrogen peroxide) and how they interact with baking soda or citric acid.
• Explore historical or cultural approaches to eco-cleaning.

Activity Scaling

• Smaller or larger groups:
• Reduce group size to 2 students for more hands-on experience per student.
• Increase group size to 3–4 for faster prep and fewer materials needed.
• Shorter sessions:
• Focus only on Steps 1–4 (research, test, improve) for a 45–60-minute lesson.
• Skip marketing and labeling if time is tight.
• Larger sessions:
• Include multiple test surfaces (glass, counters, mirrors) for more data collection.
• Allow groups to iterate formulas more than once to refine performance.

Copyright

Contributors

Supporting Program

Acknowledgements

This curriculum was developed under National Science Foundation RET grant NSF EEC-2302127. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.