Wash Well – How to Clean Your Reusable Water Bottle

General English

Level: B1-B2 Time: 60 min Focus: Prefixes

TEXT:

📋 Overview

1Warmer

2Key Words

3Comprehension

4Key Language

5Discussion

6Writing Task

📰 Article

HIGHLIGHT:

Wash well – and don't forget the lid: how to clean your reusable water bottle

Water bottles are the 'perfect environment for bacteria to grow' – follow these steps to stay clean.

Sarah Sloat · The Guardian, 05 January 2026

1Reusable water bottles are very popular. But many people don't know how to clean them. "The water bottle is just the perfect environment for bacteria to grow," says Kelly Reynolds at the University of Arizona, who studies water quality. Keeping your water bottle clean is important, but many people don't know what this means. For example, in a study of 30 people, 27 regularly refilled their water bottles without washing them. Here's what experts recommend.

2Wash your hands – and clean your phone: First, you should wash your hands because it's your hands that probably contain the bacteria. You should also clean your phone weekly, using a cloth and soap and water. Research suggests that at least 68 per cent of phones contain bacteria.

3Wash the bottle with soap, bleach or vinegar: Rinsing your water bottle with just water is not enough, explains Reynolds.

4You should clean the bottle in the sink or in the dishwasher, says Reynolds. Fill the sink with water, add a small amount of soap, bleach or vinegar, and leave it for a minute or two. Then rinse your bottle with clean water. Note: never mix bleach with any other product.

5Hot water can be better than cold: Hot water is good because it is better for creating soap bubbles which help the cleaning process. For very dirty bottles, a quick prewash with cold water is also a good idea.

6Don't forget the lid, mouthpiece or straw: These parts are often the dirtiest because they trap water so it can be easier for bacteria to grow. Use a bottle brush for these areas.

7Let the water bottle dry completely: Without moisture, bacteria have a hard time growing, Reynolds says.

8Wash regularly and sensibly: It's generally a good routine to wash your water bottle daily. This is especially important if you leave it in a hot environment such as your car because bacteria grow more quickly in warm places.

9If you can see or smell something, it's too late: Bacteria won't harm you immediately, but it can cause a slimy gel called biofilm to develop. Biofilm sticks to the sides of a water bottle and produces an unpleasant smell and taste. There could be millions of biofilm micro-organisms in a water bottle. And you only need around one hundred micro-organisms to make you sick, says Reynolds.

10Choose your bottle wisely: Metal and glass water bottles are better than plastic ones because they are antibacterial. This means they can stop bacteria and biofilm from growing. However, you should still wash these water bottles regularly.

11What happens if you don't clean your water bottle? Bacteria can easily grow in a water bottle. Reynolds recently carried out a survey at a water refill station. She tested the water in people's water bottles and found that about half of them contained bacteria and 10 per cent contained E. coli. Drinking water that contains E. coli can cause stomach pain and sickness. It's also important to clean your water bottle when you are ill, because you can reinfect yourself, says Reynolds.

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Lesson Overview

About This Lesson

This article explains what can happen when you don't clean your reusable water bottle regularly and gives advice on the best way to clean it.

Skills: Reading, Speaking, Writing
Language Focus: Prefixes (re-, micro-, anti-, pre-, bio-, non-, multi-)
Time: 60 minutes
Activities: Key words · Comprehension check · Key language (prefixes) · Discussion · Writing a hygiene poster

👈 The article is always visible on the left. Use the tabs above to navigate each section. Choose a highlight colour and select text to mark it in the article.

Warmer

Discuss the following questions in pairs.

💧

Do you own and use a water bottle? How often do you wash it with hot water?

🦠

Why do you think reusing water bottles may not be healthy?

Key Words

a. Choose the correct definition

Find the key words (in bold) in the article. Then select the correct definition (a or b).

1. antibacterial

a.containing harmful bacteria

b.designed to kill harmful bacteria

2. bacteria

a.very small organisms that can cause illness

b.dirt that you can see

3. bleach

a.a type of bacteria

b.chemical for cleaning

4. carried out

a.removed

b.done; completed

5. dishwasher

a.machine that cleans dishes

b.a person who cleans dishes in a restaurant

6. micro-organisms

a.small pieces of plastic

b.very small living things

7. moisture

a.a small amount of water

b.dry air

8. refilled

a.filled with a liquid after being empty

b.emptied completely

9. reinfect

a.to recover from an illness

b.to get ill again after recovering

10. rinsing

a.cleaning with soap

b.washing with water

11. soap bubbles

a.pieces of soap that are used for washing your hands

b.small balls of air you make when you use soap and water

12. trap

a.to keep something in a place, so it can't leave or escape

b.to release someone or something after catching them

Answer Key (a):

b. Complete the sentences

Complete the sentences with words from the previous activity in the correct form.

1.The experiment was by a team of scientists at Oxford University.

2.Try adding to your wash to make your T-shirts white again.

3.Most children love playing with in the bath.

4.Keep biscuits in a tin with a lid to keep out the .

5.Alice her coffee cup from the machine in the office kitchen.

6. the pasta under cold water stops it from overcooking.

7. in food or drinks can cause stomach problems.

8.A single drop of water from a river or lake can contain millions of .

9.Small gaps between the kitchen tiles can dirt and dust.

10.Most gyms provide spray to clean the gym equipment.

11.Doctors advise changing your toothbrush after being ill so you don't yourself.

12.I usually wash big pans by hand because they don't fit in the .

Answer Key (b):

carried out
bleach
soap bubbles
moisture
refilled
Rinsing
Bacteria
micro-organisms
trap
antibacterial
reinfect
dishwasher

Comprehension Check

Read the article and select T (True) or F (False). According to the article …

… most people wash their water bottles before refilling them.

… there is no point cleaning your hands if you don't also clean your phone.

… it's a good idea to mix bleach with vinegar.

… hot water is recommended because it produces more soap bubbles.

… you need to consume millions of micro-organisms to become ill.

… you should clean your water bottle after recovering from an illness, so you don't get ill again.

Answer Key:

F – In a study of 30 people, 27 regularly refilled without washing — so most people do NOT wash first.
F – The article recommends washing your hands AND cleaning your phone — both are important, but the article doesn't say there's no point cleaning your hands without cleaning your phone.
F – The article says "never mix bleach with any other product."
T – Hot water is better for creating soap bubbles which help the cleaning process.
F – You only need around one hundred micro-organisms to make you sick (not millions).
T – It's important to clean your water bottle when you are ill to avoid reinfecting yourself.

Key Language – Prefixes

a. Complete the prefix table

Match each meaning to the correct prefix from the box.

remicroanti prebiononmulti

Meaning	Prefix
again
against; opposing
before
life; living
many
not; without
very small; tiny

Answer Key (a): re · anti · pre · bio · multi · non · micro

b. Add a prefix to complete the sentences

Complete the sentences with the word in brackets and a suitable prefix from part a.

1.A small amount of soil can contain billions of different (organisms).

2.Our local supermarket sells (usable) bags to reduce plastic waste.

3. (virus) software will protect your computer from a cyber-attack.

4.This (purpose) tool also has a bottle opener, a knife and scissors.

5.If your clothes are very dirty, you should (wash) them first and then wash them at a high temperature.

6.My flight is a(n) (stop), 14-hour direct flight from Tokyo to London.

7. (film) is a type of bacteria that can grow in water bottles and affect the smell and taste.

Answer Key (b):

micro-organisms
reusable
Antivirus
multi-purpose
pre-wash
non-stop
Biofilm

Discussion

Discuss these questions with a partner or in small groups.

💭

Has reading this article changed how you think about cleaning everyday items? Why or why not?

🤔

Do you think most people know about the dangers associated with water bottles? Why or why not?

In Your Own Words – Hygiene Poster

Work in pairs or small groups to create an informative poster about water bottle hygiene for your school, gym or workplace. Use the frame below to plan your poster, then present it to the class.

💡 Language reminder: Use modals of obligation (must / should / have to) and prohibition (mustn't) and imperatives (wash, dry, rinse…) for giving instructions.

📌 Interesting title

❗ Why cleaning your water bottle is important

✅ Tips on how to clean a water bottle properly

⚠️ Warning section – what to avoid

💬 Useful Language

You must / should / have to wash your bottle …

You mustn't mix bleach with …

Always rinse / dry / clean …

Make sure you …

It is important to … because …