The Importance of Whirl Pak Bags: Breaking Things Down

First developed in 1959, Whirl Pak bags were originally designed to provide a reliable container for milk haulers to collect samples from bulk milk volumes. However, they've long since evolved past that original intention and play an important role in essential laboratory research around the globe.

The major benefit of Whirl Pak bags is that, by design, they created something of a "universal sampling system." A single bag can now be used for any and all tests that require not only quality control, but also product content and even legal compliance as well. They're also commonly used to transport samples from one laboratory to another for the purposes of testing, among others.

But what are Whirl Pak bags used for in a more precise nature and why are they so important to the critical work being done in labs all over the United States? The answer to those questions require you to keep a few key things in mind.

All About Whirl Paks

At their core, the types of Whirl Pak products offered by Nasco and other manufacturers are sterile, single service bags that are made out of a heavy duty, transparent material called polyethylene. Not only are they both leak proof and airtight, but they also have puncture proof tabs for your convenience.

Whirl Paks themselves are used for a wide range of different tasks in a laboratory environment, including but not limited to things like surface, forensics, genetics, biomedical and even pharmaceutical research sampling. They're used in just about every industry you can think of, from food and beverage to water to sewage, medical and beyond.

Remember that ultimately, collecting a sample in the right way is only one part of a larger story. It’s equally important to make sure that this sample gets to a lab for thorough analysis WITHOUT being compromised in any way. Despite their simple design, Whirl Pak bags are designed to do exactly that – and laboratory professionals have had an incredible amount of success with them over the years as a direct result.

Using a Whirl Pak is ultimately a very straightforward process. All you have to do is tear off the top of the bag along the convenient perforation line. After using the pull tabs to open the bag itself, simply place the sample in question in the bag and hold the bag by the wire ends. "Whirl" the bag three times to close it securely (hence the name) and bend the wire ends onto the bag itself for additional protection.

Essential Considerations About Whirl Pak Bags

As you actually begin to use your Whirl Pak bags, it's important to note that the capacity is measured when the bag is closed and the tab is folded over three times. While they are very easy to use and are undoubtedly valuable, it's also essential to understand that both the volume and dimensions of your samples are approximate.

Most Whirl Pak bag options include write-on strips that have a paper-like finish that is also helpfully smear-resistant. This means that you can write on them not only with a pencil, but also a marker or even an ordinary ballpoint pen - all in the name of keeping your lab as organized as possible at all times.

Whirl Pak's manufacturer Nasco notes that bags should NOT be used at temperatures about 180 degrees Fahrenheit, or 82 degrees Celsius. However, Whirl Pak bags CAN be frozen to any temperature should the need arise.

Other Dependable Products From Nasco

Overall, Whirl Pak sterile sampling bags are just one in a long line of examples of the reliable, innovative Nasco products that we have available at Weber Scientific. Also available is the Dehydrated Speci-Sponge Sterile Sampling System, which is a product used to collect bacteria samples from work surfaces, equipment, animal carcasses and other sources.

The system itself comes with a dry sponge that is packaged carefully inside a Whirl Pak bag. After placing the sample in the system and adding a diluent, the samples is then ready for transportation to a nearby laboratory for analysis. The Speci-Sponge Sterile Sampling System also comes with a special glove that is packaged in a way that allows the user to put it on WITHOUT touching the sampling area or the contents of the bag in any way.

Also available is the Nasco Pipet Filter Sleeve, which has plastic on one side and a fine mesh on the other that allows users to reliably draw samples from their pipet each and every time. Simply insert the sleeved pipet into your sample, draw up the sample and release it into a nearby container or petri dish. Thanks to its forward-thinking design, absolutely no obstructive particles (like pulp or seeds) can pash through the mesh - only liquid - for the most accurate results possible.

Learn more about these or any other Nasco products available as a part of our robust inventory at Weber Scientific here.

Whirl-Pak® Sterile Sampling Bags (Nasco)

  • Sterile, single service bags are made of heavy transparent polyethylene.
  • Leak-proof and airtight.
  • Puncture-proof tabs.
  • Capacity is measured when the bag is closed and tab is folded over 3 times. Volume and dimensions are approximate.
  • Bags should not be used at temperatures above 180°F (82°C). Bags can be frozen to any temperature.
  • Write-on strips have a paper-like and smear-resistant finish and can be written on with an ordinary ballpoint pen, pencil or marker.



Description/Item No. Capacity Details Mfr. Item No. Qty. Size Thickness Your Cost/Qty Purchase
Whirl-Pak® Sterile Sampling Bags
3031-90
2 oz / 58 mL Plain 01009 pack/500 3 x 5 in / 75 X 125 mm 2.25 mL
$44.80
$40.32/PK
10% discount
Sign in to Buy This item is on back-order. Allow 5-10 business days. Please call us at 800-328-8378 with any questions about availability. In Stock
Whirl-Pak® Sterile Sampling Bags
3032-00
2 oz / 58 mL write-on strip (doubles as fill line) 01064 pack/500 3 x 5 in / 75 X 125 mm 2.25 mil
$47.90
$43.11/PK
10% discount
Sign in to Buy 17 item(s) available to ship. 17 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3033-00
4 oz / 118 mL Plain 00679 pack/500 3 x 7 1/4 in / 75 x 185 mm 2.25 mil
$45.90
$41.31/PK
10% discount
Sign in to Buy 40 item(s) available to ship. 40 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3033-01
4 oz / 118 mL write-on strip (doubles as fill line) 01062 pack/500 3 x 7.25 in / 75 X 185 mm 2.25 mL
$49.30
$45.65/PK
7% discount
Sign in to Buy 207 item(s) available to ship. 207 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3033-03
7 oz / 207 mL Plain 00992 pack/500 3.75 x 7 in / 95 x 180 mm 3 mil
$59.00
$53.10/PK
10% discount
Sign in to Buy 79 item(s) available to ship. 79 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3033-06
7 oz / 207 mL write-on strip 01489 pack/500 3.75 x 7 in / 95 x 180 mm 3 mil
$61.70
$55.53/PK
10% discount
Sign in to Buy 35 item(s) available to ship. 35 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3033-78
13 oz / 384 mL Plain 01018 pack/500 5 1/4 x 7 1/2 in / 130 X 190 mm 3 mil
$72.40
$65.16/PK
10% discount
Sign in to Buy 11 item(s) available to ship. 11 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3033-79
13 oz / 384 mL write-on strip 01490 pack/500 5 1/4 x 7 1/2 in / 130 X 190 mm 3 mil
$81.00
$72.90/PK
10% discount
Sign in to Buy 37 item(s) available to ship. 37 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3034-00
18 oz / 532 mL Plain 00736 pack/500 4 1/2 x 9 in / 115 x 230 mm 2.25 mil
$64.60
$58.14/PK
10% discount
Sign in to Buy 71 item(s) available to ship. 71 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3034-01
18 oz / 532 mL write-on strip 01065 pack/500 4 1/2 x 9 in / 115 x 230 mm 2.25 mil
$69.40
$62.46/PK
10% discount
Sign in to Buy 57 item(s) available to ship. 57 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3034-65
24 oz / 710 mL Plain 01020 pack/500 6 x 9 in / 150 X 230 mm 3 mil
$84.70
$76.23/PK
10% discount
Sign in to Buy 44 item(s) available to ship. 44 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3034-66
24 oz / 710 mL write-on strip 01297 pack/500 6 x 9 in / 150 X 230 mm 3 mil
$91.10
$81.99/PK
10% discount
Sign in to Buy 66 item(s) available to ship. 66 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3034-87
24 oz / 710 mL write-on strip (homogenizer - fits all laboratory blenders) 01196 pack/500 6 x 9 in / 150 X 230 mm 4 mil
$115.00
$103.50/PK
10% discount
Sign in to Buy 42 item(s) available to ship. 42 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3034-67
27 oz / 798 mL Plain 00990 pack/500 5 x 12 in / 125 X 305 mm 3 mil
$88.30
$79.47/PK
10% discount
Sign in to Buy 22 item(s) available to ship. 22 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3034-68
27 oz / 798 mL write-on strip 01491 pack/500 5 x 12 in / 125 X 305 mm 3 mil
$105.90
$95.31/PK
10% discount
Sign in to Buy 9 item(s) available to ship. 9 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3034-88
36 oz / 1065 mL plain ( homogenizer - fits all laboratory blenders) 00994 pack/500 5 x 15 in / 125 X 380 mm 3 mil
$103.20
$92.88/PK
10% discount
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Whirl-Pak® Sterile Sampling Bags
3034-86
42 oz / 1242 mL Plain 01027 pack/500 6 x 15 in / 150 X 380 mm 3 mil
$120.80
$108.72/PK
10% discount
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Whirl-Pak® Sterile Sampling Bags
3034-91
52 oz / 1538 mL write-on strip (homogenizer - fits all laboratory blenders) 01239 pack/500 7 x 13 in / 185 X 330 mm 4 mil
$183.50
$165.15/PK
10% discount
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Whirl-Pak® Sterile Sampling Bags
3034-74
55 oz / 1627 mL plain ( homogenizer - fits all laboratory blenders) 01532 pack/500 7 1/2 x 12 in / 190 X 300 mm 4 mil
$138.10
$124.29/PK
10% discount
Sign in to Buy 23 item(s) available to ship. 23 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3034-89
55 oz / 1627 mL write-on strip (homogenizer - fits all laboratory blenders) 01195 pack/500 7 1/2 x 12 in / 190 X 300 mm 4 mil
$160.50
$144.45/PK
10% discount
Sign in to Buy 22 item(s) available to ship. 22 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3034-92
69 oz / 2041 mL Plain 01323 pack/500 7 1/2 x 15 in / 190 X 380 mm 3 mil
$138.30
$124.47/PK
10% discount
Sign in to Buy 57 item(s) available to ship. 57 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3034-90
69 oz / 2041 mL write-on strip 01515 pack/500 7 1/2 x 15 in / 190 X 380 mm 3 mil
$166.00
$149.40/PK
10% discount
Sign in to Buy 9 item(s) available to ship. 9 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3034-96
92 oz / 2732 mL write-on strip extra large 01445 Pack/250 10 x 15 in / 254 X 380 mm 4 mil
$135.60
$122.04/PK
10% discount
Sign in to Buy 42 item(s) available to ship. 42 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3034-98
123 oz / 3637 mL write-on strip extra large 01446 Pack/250 10 x 20 in / 254 X 508 mm 4 mil
$162.20
$145.98/EA
10% discount
Sign in to Buy 22 item(s) available to ship. 22 item(s) available to ship.
Whirl-Pak® Sterile Sampling Bags
3034-99
184 oz / 5441 mL write-on strip extra large 01447 pack/100 15 x 20 in / 380 X 508 mm 4 mil
$103.20
$92.88/PK
10% discount
Sign in to Buy 45 item(s) available to ship. 45 item(s) available to ship.