Dog Waste Bags: What 15 Microns Actually Means, and How Leak Tests Work

Scheduled September 2026 · Pet N Pet Editorial

Two questions come up before anyone buys a poop bag. Is it really biodegradable, and how thick is it? The second one has a precise answer that almost nobody explains properly. A micron figure is a real measurement taken to a real standard, and on its own it still won't tell you whether the bag will hold.

What does 15 microns actually mean?

A micron is a thousandth of a millimetre. Fifteen microns is 0.015 mm, which converts to 0.59 mil, because one mil equals 25.4 microns. That conversion is the first place bag comparisons go wrong: a brand quoting mils and a brand quoting microns can look wildly different while selling near-identical film.

The measurement itself is governed by a standard. ASTM D6988, the Standard Guide for Determination of Thickness of Plastic Film Test Specimens, "covers the determination of the thickness of plastic films where the thickness is used directly in determining the results of tests for various properties" (ASTM International).

The word "film" has its own definition, and it sits in a different standard. A note in D6988 points to ASTM D883, the terminology standard, where film is "an optional term for sheeting having a nominal thickness no greater than 0.25 mm (0.010 in.)."

That definition puts every poop bag on the market comfortably inside the "film" category, which is why film standards rather than sheet standards apply to all of this.

Does a thicker bag mean a stronger bag?

Not reliably, and this is the part worth understanding before you compare two spec sheets. Thickness and strength are measured by different standards, and film composition changes the relationship between them.

Two ASTM methods do the actual strength work. ASTM D1709's test methods "cover the determination of the energy that causes plastic film to fail under specified conditions of impact of a free-falling dart." Method A is specified precisely: a hemispherical dart head of "38.10 plus or minus 0.13-mm (1.500 plus or minus 0.005-in.) diameter" dropped from "0.66 plus or minus 0.01 m (26.0 plus or minus 0.4 in.)" (ASTM International).

ASTM D882 handles tensile properties, pulling film until it breaks. It covers "the determination of tensile properties of plastics in the form of thin sheeting and films," specified as "less than 1.0 mm (0.04 in.) in thickness" (ASTM International).

These test different failure modes, and both matter for a poop bag. Dart impact approximates a sudden load, the moment a heavy pickup drops into a bag you're holding by the handles. Tensile approximates a slow stretch, which is what happens when a bag hangs off a leash clip for twenty minutes.

ASTM D1709 measures impact resistance by dropping a hemispherical dart of 1.500 inch diameter from 26.0 inches onto clamped film, reporting the energy that causes the film to fail. ASTM D882 measures tensile strength by pulling film until it breaks. Because these capture different failure modes, sudden load against slow stretch, a bag can perform well on one and poorly on the other, which is why a single thickness figure cannot predict real-world durability.

What does "leak-proof" actually get tested against?

This is where marketing and metrology part company. The standard usually behind a leak claim is ASTM D3078, the Standard Test Method for Determination of Leaks in Flexible Packaging by Bubble Emission. It works by submerging a sealed package in water inside a vacuum chamber and watching for escaping bubbles.

Read its scope carefully. D3078 "covers the determination of gross leaks in flexible packaging containing a headspace gas." Two words there are doing the work: gross, and headspace. ASTM adds its own caveat, that "small leaks may not be detected by this procedure," and that detectable leak size "is dependent upon the products contained, the nature of the packaging material, and the test parameters selected" (ASTM D3078 scope).

None of that makes D3078 dishonest. It makes an unqualified "leak-proof" claim uninformative. The useful question to ask a manufacturer isn't whether the bag is leak-proof. It's which standard they ran, and what the reported value was.

Why do thin bags get the worst reviews?

Because thin film fails in a specific, memorable way. It stretches before it tears, so the failure isn't a clean split. The bag necks down, goes translucent at the stress point, and then opens up while you're holding it.

Bag size interacts with this badly. A bag that's adequate for a small dog gets loaded past its design point by a large one, and the film thins further as it stretches. That's a size mismatch presenting as a quality problem, and it's a common source of one and two star reviews across the whole category.

Two practical implications. Match bag size to dog size rather than buying the cheapest count per dollar, and compare the large-dog and bulk options on count rather than pack price. And treat the handle and seam as part of the spec, because a bag that holds fine in the middle and fails at the tie is still a failed bag.

Pet N Pet's bags are 15 microns, which is 0.59 mil, and sized for large-breed pickups rather than the category average. The value arithmetic that matters for multi-dog households is cost per bag rather than cost per pack: 1,080 bags works out to roughly $0.014 each.

Properties and boutiques buying at case volume can request wholesale pricing and bag-fit samples.

How does biobased content affect strength?

It's a fair question and the honest answer is that content and performance are separate specifications. Pet N Pet's bags are USDA Certified Biobased at 41% or 92% biobased content depending on the product. That certification describes what proportion of the film's carbon comes from biobased material. It does not describe thickness, impact resistance or degradation rate.

This is the distinction that most of the category blurs. Biobased content is a material fact, verified through the USDA BioPreferred programme. Biodegradability is a behaviour claim about what happens after disposal, governed by entirely different standards and, for a bag headed to landfill, generally not true.

For the full breakdown of what the certification does and does not cover, see our guide on whether biodegradable dog poop bags are better for the environment. For the disposal side, see is dog poop good for soil.

Frequently Asked Questions

How many microns should a dog poop bag be?

There's no regulated minimum. 15 microns, equal to 0.59 mil, handles large-breed pickups when the bag is correctly sized. Thickness is measured under ASTM D6988, with film defined in ASTM D883 as no thicker than 0.25 mm. Thickness alone doesn't predict strength, so ask about ASTM D1709 impact or D882 tensile results too.

Is 15 microns thick for a poop bag?

15 microns is 0.59 mil, toward the upper end of the range in general use for pet waste bags. Because one mil equals 25.4 microns, brands quoting mils and brands quoting microns can appear very different while selling similar film. Convert before comparing.

What does "leak-proof" mean on a poop bag?

Usually that the bag passed ASTM D3078, a vacuum bubble-emission test for gross leaks in sealed packaging holding a headspace gas. ASTM notes "small leaks may not be detected by this procedure," so a pass confirms the absence of gross pinholes and seam faults rather than performance under a wet load. Ask which test was run.

Does biobased content make a bag weaker?

Biobased content and mechanical strength are separate specifications. USDA Certified Biobased at 41% or 92% describes the proportion of biobased material in the film, not its thickness, impact resistance or tensile strength. Ask for the thickness figure and the strength test result separately.

Why do poop bags rip even when they feel thick?

Thin film stretches before it tears, thinning further at the stress point until it opens. Most reported rips are a size mismatch rather than a manufacturing fault: a bag sized for a small dog loaded by a large one. Handles and seams fail independently of the bag wall, so check those too.

SOURCES & CITATIONS

ASTM International "D1709 Standard Test Methods for Impact Resistance of Plastic Film by the Free-Falling Dart Method," retrieved 2026-08-19  https://store.astm.org/standards/d1709

ASTM International "D3078 Standard Test Method for Determination of Leaks in Flexible Packaging by Bubble Emission," retrieved 2026-08-19  https://store.astm.org/d3078-02r21e01.html

ASTM International "D6988 Standard Guide for Determination of Thickness of Plastic Film Test Specimens," retrieved 2026-08-19  https://store.astm.org/standards/d6988

ASTM International "D882 Standard Test Method for Tensile Properties of Thin Plastic Sheeting," retrieved 2026-08-19  https://store.astm.org/standards/d882

ASTM International "D883 Standard Terminology Relating to Plastics" (definition of "film", cited via D6988 Note 1), retrieved 2026-08-19  https://store.astm.org/standards/d883

USDA BioPreferred Program USDA Certified Biobased Product catalog, retrieved 2026-07-22