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"Metered Flow" in "Open Nicotine Containers" 

CPSC has indicated E-Liquid products must feature restricted-flow mechanisms, effective immediately. 

“If you manufacture or sell noncompliant [e-liquid] products, you may be subject to legal action for doing so including civil penalties of up to $110,000 for each violation, and $16,025,000 for any related series of violations.”

Consumer Product Safety Commission November 22, 2019


Fluid is honored to have Cole McDonald's invention featured in Tobacco Reporter's article, "What's in a Bottle?" on June 1st, 2021. Read the article in its entirety at

... Fluid Certify, has developed patent-pending technology to help address the glass bottle flow restriction issue.


Fluid Certify was founded by Cole McDonald, who also founded McDonald Vapor Co., an e-liquid manufacturer. In 2020, Cole passed away in a tragic climbing accident, and his mother, Lola McDonald, has kept the business going. Before Cole’s passing, he created flow restriction technology for glass bottles. Cole’s e-liquid products were packaged in unique glass bottles, and when the CPSC came out with its guidance, he conceived of his patent-pending technology to allow himself and others to maintain a level of excellence and offer alternatives to more generic plastic bottles.

The material used in Fluid Certify’s glass bottle flow restrictors is FDA food grade and offers flexibility and strength. It uses vacuum pressure and gravity to allow for repeated, uninterrupted use of a pipette. While the company is not currently mass producing the technology, it is not out of the question, according to Lola.

“Cole had a passion for the industry … he had no excuses for failure or blame—he found solutions,” Lola said of her son. His creativity and inclination for inventing opened the door to potentially “change things for the better” as he hoped to do. The company’s website,, offers more information on how to access the technology.

Marissa Dean, Tobacco Reporter 



      Fluid Dynamic holds embodiments of patent-pending, functional componentry developed to satisfy 16 CFR §  1700.15(d) “Metered Flow” provisions and implementing regulation. Embodiments of “flow-restricting” components were professionally developed and patented for use in – but not limited to – open nicotine containers: “e-liquid” or “vapor.” 

      Our in-house, industry-best prototyping facility, along with contracted manufacturers domestic and internationally, multidisciplinary attorneys, and seasoned engineers value urgency, accuracy, precision, compliance, and ingenuity. We operate nearly 24 hours daily. 

      Thousands of patent-pending “flow restrictors,” both 3-D printed inventories, are available at a fast speed, or injection molded solutions, to be in accordance with FDA standard. Send us your bottle today, and we’ll send it back hastily with an insert compatible with your bottle/aperture, at an economical price per unit, guaranteed. Large manufacturers are able to receive Fluid products at discounted rate per quantity. 


Profitable, Compliant, Today.


If your “Open Nicotine Container” (e-liquid) hasn’t yet implemented flow-restricting mechanisms, we’re here to offer the most cost-effective, rapid solution available on the market. Our in-house engineering team has worked with numerous clients, beginning with reductive process, and today, we’re able to produce any quantity required at rates vastly below anticipated polling conducted.


Call us or schedule an in-person consultation, free of charge.  
Quantitative Analysis

We’ll send your product back with a variety of Fluid inserts, meeting the “metered flow” standard, along with a compliance report specific to your brand’s respective products. 

Day 1: Getting Started 

After a brief conversation with Fluid specialists, send 5 bottles of each variety (five of each bottle sold) to our testing facility/rapid prototyping facility.

Attn: New Client Dept
McDonald Companies, LTD
50936 Hwy C
Center, Missouri 63436 

Quality, Continued. 

Formed in 1986, the McDonald Group holds vapor branding, along with numerous other businesses across many industries, having operated successfully in highly regulated industries. 

Day 14:

Within two weeks, your “nicotine containers” are shipped to your manufacturing floor, prototype ready for immediate, compliant production, regardless of quantity necessary.

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