How to Deal with an Odor in a Plastic Round Bowl?

I. Analysis of Odor Causes and Identification of Plastic Types

1.1 Determining the Source of the Odor

• Food residue: Oils and protein-rich foods can produce putrid odors after prolonged contact with plastic, especially strong-flavored foods like curry, garlic, and seafood.
• Improper cleaning: Detergent residue or humid environments can easily breed mold, producing a musty smell.
• High-temperature reaction: Exceeding the heat resistance temperature of the plastic (usually 70-120℃) can cause molecular chain breakage, releasing more chemical substances.
• Storage environment: Long-term airtight storage can easily accumulate odor molecules, especially in humid environments.

1.2 Method for Identifying Plastic Types

• No. 1 PET: Commonly found in mineral water bottles, cannot hold hot water, may release carcinogen DEHP after 10 months of use
• No. 5 PP: The only plastic that can be used in a microwave oven, this material is recommended
• No. 3 PVC: Not recommended for food packaging, releases harmful substances at high temperatures
• No. 7 PC: Contains bisphenol A, easily released at high temperatures, avoid using for infant and toddler tableware

II. Odor Removal Methods

2.1 Physical Adsorption Method

1. Drain the brewed green or black tea leaves (green tea works better).
2. Spread the tea leaves evenly in a bowl and seal it for 8-12 hours.
3. Remove the tea leaves and thoroughly rinse the bowl with clean water.

1. Put dry coffee grounds into a gauze bag or tea bag.
2. Place it in the bowl and seal it for 24 hours.
3. Remove the coffee grounds and thoroughly clean the bowl.

1. Put food-grade activated carbon granules into a gauze bag.
2. Place it in the bowl and seal it for 24-48 hours.
3. Every 100 grams of activated carbon can treat odors in approximately 1 cubic meter of space.

2.2 Chemical Cleaning Method

1. Wiping method: Wet a kitchen paper towel with white vinegar, wipe the inside and outside walls of the bowl thoroughly, let it stand for 15-30 minutes, and then rinse.
2. Soaking method: Mix white vinegar and water in a 1:3 ratio, and soak the white plastic bowl for 2-3 hours.
3. Heating method: Heat the white vinegar to about 50℃, and repeatedly wipe the inner wall with a cotton cloth dipped in the heated vinegar.
4. Applicable situations: Significantly effective for stubborn organic odors such as fishy smell and garlic smell, especially suitable for removing burnt odors after microwave heating.

1. Avoid mixing with bleach, as this will produce toxic gases.
2. The acetic acid concentration should be 5%-8%; a higher concentration may damage the sealing strips.
3. After treatment, ventilate to dissipate the vinegar smell.

1. Dissolve 1-2 scoops of baking soda in warm water.
2. Soak the dishes for 4-6 hours; for stubborn odors, extend to 12 hours or more.
3. Wipe the inner wall crevices with a soft cloth and rinse thoroughly with clean water.

1. Slice a fresh lemon and rub it directly on the inside of the bowl.
2. Alternatively, mix lemon juice and water in a 1:3 ratio and soak for 2-3 hours.
3. You can also seal the lemon slices in the bowl for 24 hours.

2.3 High-Temperature Treatment Method

1. Applicable materials: Only applicable to PP (No. 5) plastic round bowls, which can withstand high temperatures of 100-130℃. Operating Steps:
2. Place the bowl in a steamer and steam at high temperature for 10 minutes.
3. Alternatively, boil in water for 3-5 minutes.
4. Immediately rinse with clean water after steaming to prevent residual water stains from breeding bacteria.

1. Strictly prohibit the use of materials that are not heat-resistant, such as PET (No. 1) and PS (No. 6).
2. Avoid collision with metal utensils to prevent damage.
3. Disinfecting once a week can kill 99% of pathogenic bacteria.

1. Add a small amount of water to the bowl (to prevent dry heating).
2. Heat in the microwave for 30 seconds to 1 minute.
3. Let it cool after heating, then wash thoroughly.

1. Heating time should not exceed 3 minutes.
2. Do not completely seal the container during heating; leave a gap to release heat.
3. Use a medium-low heat setting to avoid exceeding the heat resistance temperature of the plastic.
4. Microwave heating for 3 minutes may release 4.22 million microplastics/cm³, so use with caution.

2.4 Sunlight Exposure Method

1. Place the washed bowl upside down in the sun.
2. Exposure to sunlight for 3-8 hours (depending on the severity of the odor).
3. Open all sealing rings during sun exposure to allow the odor to fully dissipate.

1. Polycarbonate PC material should not be exposed to sunlight, as it may cause the material to yellow and become brittle.
2. Polypropylene PP material should not be exposed to sunlight for more than 6 hours to avoid aging.
3. Avoid exposure to direct sunlight at noon to prevent plastic deformation.
4. Colored plastics may fade, so use with caution.

2.5 Professional Cleaning Agents

• Must meet Class A food-grade safety standards
• Prioritize products with NSF certification
• Choose fragrance-free or natural plant-based formulas to avoid secondary pollution from chemical fragrances

• Domestic Brands: Kaimi, Libai, Axe Brand, NetEase Yanxuan, Walch, etc.
• International Brands: Simple Green (NSF certified), Frosch (German brand), etc.
• Professional Products: Sanqiao Food Industry Acid-Base Cleaning Agent (passed quality inspections for 13 consecutive years)

III. Comprehensive Treatment Solutions

3.1 Treatment Process for Odors in New Bowls

3.2 Treatment Process for Odors After Use

3.3 Treatment Plan for Stubborn Odors

• Ozone Treatment: Use an ozone generator (concentration 0.1ppm, duration 30 minutes), achieving an 88% degradation rate for aldehydes and ketones.
• Gradient Heating Method: Place the plastic product in a 70℃ environment for 30 minutes, then gradually increase the temperature to 120℃ (only applicable to PP material), which can remove more than 90% of the odor.
• Professional Cleaning: Use an NSF-certified product. Deep cleaning with certified food-grade cleaning agents

IV. Safety Precautions

4.1 Material Safety Confirmation

• PVC (No. 3): Easily releases harmful substances at high temperatures; not recommended for food packaging.
• PC (No. 7): Contains bisphenol A, which is easily released at high temperatures; prohibited for use in infant and toddler tableware.
• Unmarked or low-quality plastic: If there is a pungent odor that cannot be removed, it is recommended to discard it immediately.

4.2 Operational Safety

• White vinegar and baking soda must be used separately; mixing them will produce harmful gases.
• Avoid using strong acids and bases, as they may damage the plastic surface.
• Maintain ventilation during use to avoid inhaling irritating gases.

• Strictly control temperature and time to avoid plastic deformation or the release of harmful substances.
• Do not seal during heating to prevent the risk of explosion.
• Use heat-resistant gloves to avoid burns.

• Do not use steel wool or other hard objects, as they will damage the plastic surface and increase the risk of chemical migration.
• It is recommended to use a soft cloth or sponge with a mild detergent.
• Regularly inspect the white plastic bowls; if there are scratches, deformation, or cracks, discontinue use immediately.

4.3 Food Safety Considerations

• If the odor persists for more than two weeks after treatment, it is recommended to stop using the bowl.
• If the odor intensifies after heating, it indicates that harmful substances may be released, and the bowl should be discontinued immediately.
• If the plastic shows signs of aging, such as yellowing or deformation, it is recommended to replace it.

V. Daily Use Suggestions and Preventive Measures

5.1 Correct Usage Habits

• Strictly prohibit holding food exceeding 70℃ (for PET and PS materials).
• Although PP material can withstand 120-130℃, prolonged contact with high temperatures should be avoided.
• Hot food should be cooled to room temperature before being placed in plastic round bowls.

• Avoid storing high-fat, high-sugar foods for extended periods (the boiling point of oil easily exceeds the heat resistance limit of plastic).
• Avoid storing acidic foods (such as vinegar, lemon juice, and tomato sauce) for more than 24 hours.
• Avoid storing strong-smelling foods (such as garlic, curry, seafood), as these odors are easily absorbed by plastic.

• Only PP material can be microwaved, and a medium-low temperature setting should be used.
• Heating time should not exceed 3 minutes, and the lid must be opened during heating.
• Strictly prohibit placing ordinary plastic round bowls in ovens or steamers.

5.2 Cleaning and Maintenance Methods

• Clean immediately after use to avoid food residue.
• Pay special attention to cleaning the sealing strips, corners, and other areas where dirt and grime easily accumulate.
• Use a neutral detergent; avoid using detergents containing bleach.

• PP material bowls can be sterilized by scalding with boiling water for 5 minutes weekly.
• Use a soft cloth or sponge for cleaning; avoid using hard objects such as steel wool.
• After washing, invert the bowls to drain the water and store them only after they are completely dry.

• Perform deep cleaning at least once a week.
• Use a baking soda or white vinegar solution to soak and remove stubborn stains.
• Regularly inspect the bowls and replace them promptly if any problems are found.

5.3 Storage Methods

• Ensure that the bowls are completely dry before storing to prevent bacterial growth in humid environments.
• Store in a well-ventilated place to avoid odor accumulation in confined spaces.
• Activated carbon packs can be placed in the storage container to continuously absorb odors.

• Use different bowls for raw and cooked food to avoid cross-contamination.
• Bowls with odors should be stored separately to avoid contaminating other tableware.
• Bowls that are not used for a long time should be washed, dried, and then stored.

• Visible scratches or wear
• Yellowing or blackening
• Cracks or damage
• Unremovable odor

5.4 Material Selection Suggestions

• PP (No. 5) material: The only material suitable for microwave heating, relatively safe
• Food-grade certification: Choose products marked "for food contact"
• No decorative patterns: Avoid the risk of heavy metal migration from colored patterns
• Purchase from reputable sources: Choose well-known brands to avoid substandard products

VI. Methods