What Size Trash Bag Do You Need for a 15 Gallon Trash Can?
15 gallon trash bags are designed to fit standard kitchen, bathroom, and office trash cans in the 13-15 gallon range, and certified compostable versions offer the same fit and strength as conventional plastic while breaking down under composting conditions rather than persisting as plastic waste. GreeneWrap's 13-15 Gallon Compostable Trash Bags with Drawstring measure 25 x 32 inches, are 1.2 mil thick, and are sold in 30-count rolls (SKU GW-15D30, $19.49), making them a direct match for most 13-15 gallon bins found in kitchens, bathrooms, and small offices.
Choosing the right size matters for both performance and cost. A bag that's too small won't cover the rim of the can properly, while an oversized bag bunches up and wastes material. This guide covers what compostable 15 gallon trash bags are made of, how they break down, what certifications back up compostability claims, and how to use them correctly.
What Are Compostable 15 Gallon Trash Bags?
Compostable trash bags are bags made from plant-based materials, typically PLA (polylactic acid, derived from fermented plant starch such as corn) and PBAT (a biodegradable polyester), sometimes blended with cornstarch. Unlike conventional plastic bags made from petroleum, these materials are designed to break down into carbon dioxide, water, and organic matter when exposed to the right composting conditions, leaving no toxic residue and no microplastics behind.
It's worth being precise about terminology here, because "compostable" and "biodegradable" are often used interchangeably but mean different things. Biodegradable simply means a material will eventually break down through biological activity, with no guaranteed timeframe, no guaranteed end result, and no third-party testing requirement. Compostable is a certified, tested claim: it specifies the conditions required, the timeframe for breakdown, and the percentage of the material that must disintegrate. GreeneWrap products are always described as certified compostable, never simply biodegradable, because the certifications behind them (detailed below) require independent lab verification.
Composting, whether at home or industrially, only begins when a bag is exposed to heat, moisture, and microbial activity. A compostable bag sitting in a kitchen drawer, in a landfill, or in an ordinary trash bin is not actively composting, because those environments don't provide the conditions the material needs to break down.
How Do Compostable Trash Bags Actually Break Down?
Breakdown happens in two general settings, and the distinction matters for anyone choosing a compostable bag: home composting and industrial composting.
Industrial composting facilities maintain high temperatures (55-60°C), controlled humidity, and concentrated microbial activity that accelerates decomposition. Under the ASTM D6400 standard (used in the US) and EN 13432 (used in the EU), certified compostable materials must achieve 90% disintegration within 84 days (ASTM D6400) or 90 days (EN 13432) under these industrial conditions.
Home composting relies on ambient temperature and a standard backyard compost environment, without the heat and controlled conditions of a commercial facility. The TUV OK Compost HOME certification requires 90% disintegration within 180 days under these home conditions. This timeline is longer than industrial composting because backyard piles run cooler and less consistently than commercial systems.
Both pathways depend on active biological conditions. Like all organic materials, compostable bags decompose more slowly in landfill conditions where oxygen and moisture are limited, and compostable bags are designed for active composting environments, not landfills. They also will not break down in the ocean or while sitting in an ordinary trash bin, since none of those settings provide the heat, moisture, and microbial exposure that composting requires.
What Certifications Should 15 Gallon Trash Bags Have?
Certifications are the difference between a genuine compostable claim and marketing language. Because compostability claims can't be verified by looking at a bag, third-party certification is the only reliable way to confirm a product actually performs as described. When evaluating any compostable trash bag, look for the following:
- BPI Certified: requires independent third-party laboratory testing before certification is granted. It is not a self-declared claim, and products must demonstrate compliance with compostability standards to earn it.
- OK Compost HOME: confirms the product meets the TUV Austria home composting standard, verifying 90% disintegration within 180 days in a standard backyard compost environment.
- OK Compost INDUSTRIAL: confirms the product meets industrial composting requirements, verifying 90% disintegration within the ASTM D6400 or EN 13432 timeframes under commercial facility conditions.
- ASTM D6400 compliant: the US standard for compostable plastics, covering disintegration, biodegradation, and ecotoxicity.
- EN 13432 compliant: the equivalent EU standard, used across European composting infrastructure.
- TUV Austria Certified: the certifying body behind the OK Compost HOME and INDUSTRIAL marks.
GreeneWrap's 13-15 Gallon Compostable Trash Bags carry all five of these: BPI Certified, OK Compost HOME Certified, OK Compost INDUSTRIAL Certified, TUV Austria Certified, and compliance with both ASTM D6400 and EN 13432. This means the bags are backed for both home and industrial composting environments, not just one.
GreeneWrap products are also PFAS free and fluorine free, confirmed by the manufacturer. This is specific to GreeneWrap; some compostable products on the market may contain PFAS, so it's worth checking certification and manufacturer statements directly rather than assuming all compostable bags share this attribute.
How to Spot Greenwashing in Compostable Trash Bag Claims
Not every bag labeled "eco-friendly" or "green" is certified compostable. Because compostability is a technical, testable claim, the most reliable way to verify it is to look for a specific certification mark and standard, rather than a general environmental claim. A few practical checks:
- Look for a certification logo (BPI, OK Compost HOME/INDUSTRIAL, TUV Austria) rather than just the word "compostable" printed on the packaging.
- Check whether the standard cited is ASTM D6400 or EN 13432. These are recognized, testable standards; a product that only says "biodegradable" without one of these references has not been through the same certification process.
- Note whether the claim distinguishes home compostable from industrially compostable. A product certified only for industrial composting will not break down reliably in a backyard compost pile within a home composting timeframe, and the label should say so.
- Be cautious of vague claims like "eco-friendly" or "green" used on their own, without a certification body or standard attached. These terms carry no testing requirement behind them.
What Are 15 Gallon Trash Bags Used For?
15 gallon trash bags are one of the most common bag sizes for everyday household use. They're typically sized for:
- Kitchen trash cans that see daily use but don't need the larger 30-45 gallon capacity of a kitchen-and-yard combo bin.
- Bathroom and small office wastebaskets that generate lighter, drier waste.
- Households looking for a single mid-size bag that works across multiple rooms without switching sizes.
For households generating a mix of waste types, it can help to think in terms of bin size rather than one-size-fits-all. GreeneWrap's catalog runs from 1-2 gallon bags for small kitchen food scrap bins up through 90-95 gallon bags for yard waste and heavy-duty jobs, with the 13-15 gallon drawstring bag sitting in the middle as the standard everyday size. Larger sizes, roughly 50 gallons and up, are heavier-duty (2 mil) and better suited to contractor, job-site, or yard-waste use rather than daily kitchen trash.
How Do You Use 15 Gallon Compostable Trash Bags Correctly?
Compostable bags perform differently from conventional plastic in a few specific ways, and using them correctly helps them perform as intended:
- Wet waste: compostable bags are suitable for wet food scraps for short-term use, but moisture accelerates the breakdown process. Don't leave wet waste sitting in the bag for more than 1-2 days.
- Sharp objects: broken glass, bones, and other sharp items can puncture any compostable bag. This is a general limitation of compostable materials, not specific to any one brand, so it's worth double-bagging or wrapping sharp waste separately.
- Storage: compostable bags are stable under normal indoor storage conditions, meaning a cool, dry place away from direct heat or excess humidity. Use them within 12 months of purchase, since the material is designed to remain stable in storage but is not intended for indefinite shelf life.
- Disposal: check whether your municipal green-bin or food waste program accepts certified compostable bags, since acceptance varies by city and facility. If no municipal program is available, home composting is an option for bags certified under OK Compost HOME, provided your backyard pile maintains reasonably active conditions.
Following these guidelines helps the bag perform reliably through its normal use cycle and sets it up to actually break down once it reaches an active composting environment, rather than sitting unused past its stable storage window.
FAQ
Are compostable 15 gallon trash bags as strong as regular plastic bags?
Certified compostable bags are engineered to hold typical household waste loads for their size class. GreeneWrap's 13-15 gallon drawstring bags are 1.2 mil thick, which is comparable to standard household trash bags in that size range. As with any bag, sharp objects such as broken glass or bones can puncture the material.
Can I put a compostable 15 gallon trash bag in my regular trash bin?
Yes, compostable bags can be used in a regular trash bin the same way a conventional bag would be, but composting will not occur there. Like all organic materials, compostable bags decompose more slowly in landfill conditions where oxygen and moisture are limited. They're designed for active composting environments, not for the trash bin or landfill itself.
What's the difference between home compostable and industrially compostable?
Home compostable (certified under TUV OK Compost HOME) means the product will reach 90% disintegration within 180 days in a standard backyard compost pile at ambient temperature. Industrially compostable (certified under BPI or ASTM D6400/EN 13432) means it reaches 90% disintegration within 84-90 days, but only under the higher heat (55-60°C), humidity, and microbial activity found in a commercial composting facility. A bag certified for both, as GreeneWrap's are, works in either setting.
Are compostable trash bags the same as biodegradable trash bags?
No. Biodegradable is a general term meaning a material will eventually break down, without a required timeframe, end result, or independent testing. Compostable is a certified claim, tested by a third party against a specific standard (such as ASTM D6400 or EN 13432) and a specific timeframe. GreeneWrap products are always labeled certified compostable rather than biodegradable, because the certifications behind them have been independently verified.
Do compostable 15 gallon trash bags contain PFAS?
GreeneWrap products are PFAS free and fluorine free, confirmed by the manufacturer. This applies specifically to GreeneWrap products; other compostable brands may vary, so it's worth checking manufacturer statements or certification documentation directly when evaluating any compostable bag for PFAS content.