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If you know how to sterilize plastic bottles, you will be able to reuse them for storing baby milk, water, or other household purposes in a safe way. However, they can also collect bacteria which can be harmful to health.
Most reusable plastic bottles, such as baby bottles, are made of polypropylene plastic. If unsure, always check what type of plastic that the bottle is made of before sterilizing a plastic bottle.
Tip: Use a Sterilizer Dryer for Bottles
Sterilizing plastic bottles can be easy with the right equipment. You can use a baby bottle sterilizer that also does the drying for you. This takes out the extra step of waiting for it to dry. When you’re going through several bottles a day, especially as a new mom, you will be relieved that this sterilizer does the drying for you.
The sterilizer and dryer are also good for any type of reusable bottle, such as glass baby bottles. You won’t need to use harsh chemicals. You can use heat, microwave, or natural oxygen bleach to help you kill the bacteria.
Read on to find out how to sterilize plastic bottles for feeding your baby or other drinking and storage purposes.
How to Sterilize Plastic Bottles
Before you start
Wash the bottle before first use
You will want to wash the bottle with dish soap and warm water before the first use. That’s because there are chemicals during the manufacturing of the bottles that can’t be removed by heat sterilization.
Check the plastic material
What is your plastic bottle made of? The material should be heat resistant to boiling, microwaving, and resistant to cleaning with oxygen bleach. A quick check is by looking at the recycling number, usually located at the bottom of the bottle.
If you bought a plastic baby bottle, it is usually made of polypropylene. You can check for the plastic number 5 and/or PP that can usually be seen at the bottom of the bottle.
Plastic Number 5 – PP (polypropylene) is a common plastic material that is microwave safe and heat resistant. Sterilizing can be as simple as the sanitizing cycle on your dishwasher or dipping it in boiling water, as discussed step-by-step below.
Some types of plastic will melt with heat or are single-use only. Usually, you can find single-use plastics with take-out coffee and drinks.
Method 1: How to Sterilize Plastic Bottles with a Natural Oxygen Bleach Solution
We recommend oxygen bleach because you’re likely sterilizing a plastic bottle to use for eating and drinking for your baby and family. Oxygen bleach kills bacteria. However, it does not have hazardous toxicity like traditional bleach. It’s environmentally sustainable, too.
Step 1: Combine Oxygen Bleach with Water
Pour about 1 gallon (3.8 liters) of water into a container or washbasin. Then add 1 teaspoon (nearly 5 mL) of oxygen bleach and mix well to make a sterilizing solution. The bleach should be unscented. Use warm water (at least 75°F) or hot.
Also, the basin you use should be large enough to accommodate all the bottles so that water covers them completely. If you want to sterilize many plastic bottles at once, use a large 2-gallon or 3-gal container and add 2 or 3 tsp of oxygen bleach, depending on the number of bottles.
Step 2: Make the Bottle Pieces Ready to Sterilize
Before submerging bottles in the bleach solution, you need to remove any nipples (when it comes to baby bottles), caps, and other parts. Why is this important? Once you have taken these accessories apart and disassembled plastic bottles altogether, you’ll prevent germs and bacteria from getting stuck in small crevices.
Step 3: Submerge the Bottles
The bottles need to be submerged for 5 minutes to get the best results. If you are in a hurry, allow them to soak for at least 2 minutes. They must be entirely soaked under the solution to keep the bubbles from appearing in the bottom of your bottles.
There’s another thing to do at this stage if you want to sterilize baby bottles. Use nipple and bottle cleaning brushes to help reach all the crevices. The oxygen bleach solution should be squeezed through the tiny holes of the nipples.
Step 4: Remove and Air Dry
Rinse the bottles thoroughly. The oxygen bleach breaks down into water molecules as it dries.
Method 2: Sterilize the Plastic Bottles by Running Them Through Dishwasher
First, take a look at your dishwasher’s settings panel. Look for an option that is a button or dial for “Sanitize” or “Sani-rinse”.
This method doesn’t always work because not every dishwasher comes with the sanitizing option. If it doesn’t, the dishwasher won’t produce the heat that is high enough to effectively sterilize the plastic items. If not for baby use, you can try using the hottest water setting and run a heated dry cycle.
Before you start, also check to see if your plastic bottles are dishwasher safe. Only plastics that are dishwasher safe can be sterilized with heat.
Step 1: Check Your Dishwasher’s Owner’s Manual
Make sure your dishwasher has a “sanitize” cycle. This means it is capable of eliminating 99.9 percent of germs and household bacteria. That’s why you should review the manual first.
Check whether it’s certified to NSF/ANSI 184. If it doesn’t, forget this method unless you intend to buy a new dishwasher.
Step 2: Disassemble Your Plastic Bottles
Next, you need to separate all the parts of your bottles. Simply take them apart before placing the plastic items in the top rack of your dishwasher. This step is often overlooked although it plays an important role in sanitizing.
Step 3: Place the Bottles in Your Dishwasher
Now that you’ve taken apart the pieces of the bottles, you can place them in the top rack. Make sure the bottles are positioned top-side down.
Step 4: Loading Small Plastic Bottle Pieces into the Dishwasher
There is another essential step to take before running the bottles through the dishwasher.
Whether it’s a plastic baby bottle or a glass bottle, you’ll find a bunch of small pieces that need to go into the dishwasher, too. It’s about small parts, such as rings, caps, pacifiers, and valves.
They can be placed in a dishwasher basket. Very small items can use the help of a dishwasher bag. Then, you can carefully secure the bag inside the dishwasher basket or along the side of the top rack.
That’s because these small pieces can easily fall out and get damaged when they get in direct contact with the dishwasher’s heating elements.
Step 5: Run a Sanitize Cycle
As mentioned above, it’s best to choose a sanitizing setting. If not possible, you should select a hot-water cycle with high heat drying.
After putting in the detergent, press the sanitize and start buttons. Before you remove the bottles, wait until your dishwasher does the whole sanitize cycle, which can take more than an hour. Never stop it early because your bottles will not be sterilized properly.
Method 3: Sterilize Your Bottles in the Microwave
Another straightforward approach to sterilizing plastic bottles is using a microwave. In fact, you use steam power to sterilize bottle pieces.
Here’s how to do it.
Step 1: Use Microwave-Safe Bottles
You want to be sure that plastic bottles are microwave-safe. Take a closer look at the packaging before placing them in your microwave. Also, make sure the microwave is perfectly clean.
Step 2: Take the Pieces Apart
Step 3: Fill Your Bottles with Cold Water
The bottles should be filled halfway with water before being set in the microwave.
Use tap water and make sure it’s cold. This will make it less likely for harmful chemicals (like lead) to enter the water.
You may be wondering why this step is required. When setting the bottles in your microwave and turning it on, the water in them is going to create steam. It can do a great job of sterilizing plastic bottles.
Step 4: Place Small Pieces in a Glass Water-Filled Bowl
Take a glass bowl (check if it’s microwave-safe) and fill it with water to cover smaller pieces like rings and nipples. The water should be deep enough. That said, ensure that every piece is completely covered.
Step 5: Microwave Them on High
Once you’ve placed the smaller pieces and bottles in the microwave, hit the high button.
By microwaving your plastic items for about 90 seconds, you will kill all the germs. Don’t stop the microwave early. Wait for it to finish.
Step 6: Leave Them to Dry
Remove the items from your microwave with oven mitts. If you do it with bare hands, make sure they are clean and the bottles aren’t hot to the touch. After emptying the water from the glass bowl and bottles, put them on a drying rack to air dry.
FAQs About How to Sterilize Plastic Bottles
How to Sterilize Plastic Bottles at Home?
Once you have washed your bottles thoroughly and removed sticky labels, soak them in a solution of the dishwasher, hot water, and soap.
After rinsing the bottles with dish soap and water, get a pot of clean water to a rolling boil.
Carefully place the plastic bottles in to sterilize in the boiling pot of water.
Leave the plastic bottles in the boiling water for 5 to 15 minutes.
Use tongs to collect them out of the hot water and let them dry on a clean surface.
What’s the Best Method for Sterilizing Plastic Bottles and Other Items?
My favorite method to sterilize plastic baby bottles is to use a machine that sterilizes with steam and automatically dries them. It’s an excellent way to sterilize the number of baby bottles that go through the day because it doesn’t require any added chemicals.
As well, I used to boil the baby bottles in hot water and then let them dry. However, it’s been a lifesaver that takes out the extra fiddly steps. I don’t even have to wait for the baby bottles to dry anymore.
As soon as they’re washed, I put them in the baby bottle sterilizer. After we were done with the baby bottle stage, I still use the machine sterilizer to sterilize things around the house, from pet medicine syringes to plastic bottles we want to reuse.
If you’re looking for the best way to sterilize your plastic bottles, I’d recommend getting a machine steam sterilizer.
Another easy way to sterilize plastic bottles is to use a microwaving sterilizer bag. You can also get the tray version that is made to fit plastic baby bottles. However, these second and third options will not dry the bottles for you. Although, I must say that it is great for the budget.
Now that you know the different methods on how to sterilize plastic bottles, you can choose the right way for you.