performance

Summary, Containment Testing of Saf T Flow Chemical Fume Hoods

DR. ROBERT HAUGEN
Director of Product and Technology Development

Robert K Haugen  currently designs chemical laboratory containment equipment and develops new relevant technologies for Flow Sciences Inc.in Leland, North Carolina. He has also held positions at Kewaunee Scientific, Jamestown Metal Products, and St. Charles Manufacturing in similar capacities for 31 years. Previously, he did analytical chemical work at the University of Illinois (DNA, wastewater, and crop research) and Lawrence Livermore Labs in California (nuclear weapons research).

Dr. Haugen began his career as a curriculum writer for the Illinois Office of Education, developing texts on energy, urban management, and industrial pollution topics.

He received all his degrees from the University of Illinois in Urbana-Champaign, and is currently a member of the American Society of Heating, Refrigeration, and Air Conditioning Engineers, the American Chemical Society, and the National Fire Protection Association. He has participated in the development of both ASHRAE 110-1995 and the current 2016 update.

Over a period of time ranging from 11/6/2013 onward, the range of standard Saf T Flow Fume Hoods shown below were tested by Flow Sciences using the ASHRAE 110-1995 methodology.  Details of the individual tests are available separately from Flow Sciences; total results are summarized below:

ASHRAE 110-2016 Saf T Flow Test Data Summarized by Volumetrics, Hood Description, and Catalog #:

Procedures and Equipment:

In each test position, face velocities were established using a TSI thermal anemometer and a velocity grid specified in section 6.2 of the ASHRAE 110 standard.

The ASHRAE 110-2016 test procedure used employs a sulfur hexafluoride diffuser set at 30 PSI with a diffusion rate of 4 lpm. Tests were run with the mannequin in place for 5 minutes and SF6concentrations in the mannequin-breathing zone recorded.

An SME (sash movement effect) test was run for a total of two minutes and included opening and closing the vertical sash twice in 30-second intervals over the two minute run. Tests were run with the mannequin in place and SF6 concentrations in the mannequin-breathing zone recorded.

Relevant illustrations from the standard are shown below:

Approved ASHRAE Standard 110-2016 used as an overarching methodology

Ejector Assembly Used in ASHRAE110 and Human as Mannequin Tests

 

In each test position, face velocities were established using a TSI thermal anemometer and a velocity grid specified in section 6.2 of the standard.

The ASHRAE 110-2016 test procedure used employs a sulfur hexafluoride diffuser set at 30 PSI with a diffusion rate of 4 lpm. Tests were run with the mannequin in place for 5 minutes and SF6concentrations in the mannequin breathing zone recorded.

An SME (sash movement effect) test was run for a total of two minutes and included opening and closing the vertical sash twice in 30 second intervals over the two minute run.  Tests were run with the mannequin in place for and SF6 concentrations in the mannequin breathing zone recorded.

Relevant illustrations from the standard are shown below:


The HAM Containment Test

 

While comprehensive dynamic tests are not a part of ANSI/ASHRAE 110-1995, it is evident that the low face velocity fume hood vulnerabilities might go unmeasured unless kinetic challenges are systematically introduced into our Safe-T Flow evaluation program.

The researchers decided to “borrow” a kinetic challenge test rather than design a hood to pass the lone and rather perfunctory dynamic sash movement test (SME Test) already in the ASHRAE 110 standard.

The Human as Mannequin Test

Funded jointly by Lawrence Berkeley National Laboratory and the California Energy Commission in 2005, the ECT group investigated kinetic challenges to low velocity fume hoods by developing a special test that used a human with an air sampler in front of a fume hood manipulating equipment in a specifically defined manner.

For this adapted version of the HAM test, the researchers placed a breathing zone monitor on a tripod stand so it and the analysis equipment would not be jarred by the moving operator.  Final array is shown below in Photo #1.  The HAM tests involve conducting a series of choreographed activities using objects located within the hood. The objects consist of two 100 ml measuring cups, a 100 ml scoop, and a spatula.

The modified timed sequence of activities follows the layout shown in Photo # 1

  1. Stand at hood opening with arms to side.
  2. Insert and remove hands and arms
  3. Move objects #1 through #4 from six inch line to twelve inch line
  4. Exchange position of objects. (1 to 2, 2 to 3, 3 to 4, and 4 to 1)
  5. Transfer liquid from scoop #1 to scoop #2.
  6. Place spatula in empty cup.

Each sequence of activities is conducted over a period of approximately 70 seconds


Conclusion:

All Flow Sciences Saf T Flow fume hoods pass ASHRAE 110-1995, using criteria set forth in ANSI/AIHA Z 9.5, Section 6.3.7.  A containment level of 0.050 PPM must be achieved in each test to pass, using the pass-fail level of 0.050 PPM established in AIHA Z 9.5; all data from all tests are much lower than this!

ASHRAE 110-2016 Saf T Flow Test Data Summarized by Volumetrics, Hood Description, and Catalog #:

Photos of Hoods under Test



How Does the FSI Fume Hood Stack up on The Top Ten Lab Worker Needs?

Abstract:

Lab Manager magazine1 recently published a feature entitled Survey Says. In this article was a section called What You Need to Know Before Buying a Fume Hood.”   Ten factors were named in over half the lab managers surveyed. We will review and analyze these factors and discuss how Flow Sciences addresses them. Whatever we’re doing, most of our customers seem to like it a lot!

Introduction:

In the December 2018 Lab Manager, the article Survey Says, cites the top ten things managers look for in a chemical fume hood:

We decided to look at this “top ten list” and see how the Flow Sciences fume hood stacks up. We discovered that these sought-after qualities really lead to a shopping list of features, most of which are standard on the Saf T Flow hood…..read on!


Top Ten features reviewed:

1 – Performance of Product:

Before performance can be discussed, Flow Sciences always asks our customer what application is being undertaken in the fume hood.

This is very important. Most containment manufacturers have valuable and worthwhile tests they perform on standard product. These tests may be generally useful, but not relevant if the customer, for example, requires a hood with a larger than standard sash opening. Or if the chemicals being used in the hood have unique characteristics that require special linersor wash-down systems.

Many lab managers may not realize that these factors, if not considered, will lead to poor performance or dangerous conditions. Once special needs are considered, Flow Sciences can provide testing information on standard product, or run tests on the modified hood and document the effectiveness of the modifications.

Both of the non-standard products shown above had outstanding containment both on ASHRAE 110-2016 and the “HAM” test developed by Tom Smith of 3-Flow and Lawrence Berkeley National Lab 2.


2 – Durability of product.

Flow Sciences believes fume hoods should have a minimum serviceability of twenty years. If lightly used, most fume hoods made in the US will last this long. If hoods must be moved or modified within this time period, or if they are heavily used, or used for applications different than those specified, they may not last one year, or never work at all!

We illustrate below several design “weak points” of many common fume hoods sold today and better ways to design a more robust product.

        A – Fume hood sash system. Such a system should work reliably, need few service adjustments, and never break down. Shown below are examples of an inferior and a good sash counterbalance system:

        B – The fume hood support frame should be a stand-alone heavy-gauge system! If equipment collapses or a fire breaks out, such a system prevents hood collapse if key liner panels get broken!

        C – Flexible Plumbing is important today. It used to be plumbing in fume hoods was hard- piped. Such plumbing had solders which could rattle loose in shipping and leak when hooked up to pressurized services in the lab. Newer plumbing is flexible with no welds at all! This system hooks up quickly to mated pressurized fittings in the field. Also this flexible system allows service gasses to be changed or modified if research requirements change!

        D – Flexible Counter Top Design! This top actually slides out for replacement or repair. The lift-up airfoil allows cords to be routed to outlets without resting on the airfoil top where the sash will run into cords every time it is closed!


3 – Safety and health features. The primary purpose of a chemical fume hood system is user safety. Features of design and construction should work as a system to assure this. We recommend any fume hood demonstrate safety by compliance with at least five published standards:

 

        A – ASHRAE 110 2016. The use of a gas diffuser inside the fume hood and a mannequin with a breathing zone detector to assure that less than 0.05 ppm (Parts per million) of tracer gas gets into the breathing zone of the mannequin during a five-minute test.

        B – The Human as Mannequin Test. Cited earlier, the test uses a gas diffuser and simple lab equipment inside the fume hood which is manipulated by a test subject with a breathing zone sensor. A pass/fail reading of less than 0.05 PPM (parts per million) should again be used.

        C – The UL 1805 Standards. Widely accepted in the US and Canada, UL 1805 sets forth both a physical testing regimen for safety glass, epoxy work tops, and liner materials and an outline for internal wiring of the fume hood. Most major fume hood manufacturers comply with these standards, products in conformity must have a UL 1805 compliance tag visible somewhere on the fume hood exterior.

        D – Surrogate Powder Containment and Balance Stability data for fume hoods involved in pharmaceutical weighing and dispensing procedures. More and more fume hoods are involved in procedures where pharmaceutically active compounds are manipulated. These materials do not diffuse in the same way vapors and gasses do. If such materials are used in a fume hood, containment data regarding powders must be provided using an appropriate test room and collection equipment. Procedures should reflect the types of manipulation to be used by the customer.

        E – ISO 9001:2015 Certification of the manufacturing facility. All materials and procedures must be trackable and verifiable to assure construction material, flame spreads, certifications, and other assembly issues relevant to the safety and durability of the equipment are solidly documented.


4 – Easy to Clean. Any chemical fume hood should be easy to clean. For scrupulous cleaning, fume hood components must be chemically resistant and easy to access for cleaning.

 

A – Chemical resistivity. All paints must be certified against the SEFA (Scientific Apparatus Manufacturers’ Association) standard set forth in SEFA 8-M-2010. In this standard, paints are tested against scratching, abrasion, and chemical resistivity. Liners must meet NFPA Class A flame spread requirements.

        B – Access to all exposed surfaces. All exposed surfaces inside the fume hood containment area must be completely accessible for cleaning. Illustrations below show how this is achieved in the Flow Sciences product:


5 – Ergonomic ease of operation. Several features help satisfy this criterion. The glass top panel allows complete vision of the hood interior. Great for tall distillation columns or thermometers on tall equipment. The chain drive sash is easier to move up and down than any other system and does not wear out. Either bright T-5 fluorescent lighting or high output LEDs are available for clear vision of the very deep 25 7/8” hood interior. Base cabinets or a table for seated work are available. We also have built in a very stable anchoring system for scaffolding. All our standard hoods come with this anchoring system. To maximize flexibility needs inside a lab, Fume hoods are available in 1’ width increments from 3’ to 8’.


6 – 7 – 10 – Value for Price Paid, Low operating costs, Cost of ownership

 

These three lab manager survey questions are so interwoven, that the author will lump them together for analysis. The sixth and seventh issues, value and operating cost, cannot accurately be discussed as separate items. When one purchases a fume hood, the hood purchase price is just the tip of the iceberg4 as far as operating cost.

As seen in the graph above from an article written last year, a “low cost” hood inherently consumes more energy than a hood designed to save energy by exhausting less air. Over just five years, the engineered hood (red line, higher first cost) has consumed $30,000 of energy, while the low cost hood has consumed $64,000! (This is not a good way to save $2,700 on purchase price!)

 

In fact, even asking someone to evaluate hood price/value and energy savings separately is a fatal error! The author invites anyone interested to read the cited article and the various mathematical inputs that fostered the graph shown above.

 

So value, properly evaluated, must include energy efficiency!

 

Let’s now look at the tenth survey questioncost of ownership.  This tenth item on Lab Managers survey list is clearly also part of the discussion we are now having regarding value and energy efficiency. The author regards valueand energy efficiency as inputs into discerning cost of ownership!

 

Here’s the headline: Cost of ownership will always favora contemporary, engineered energy-efficient fume hood! As an example, the Flow Sciences energy-efficient hood has remarkable containment down to 60 FPM at an 18” sash opening. Check out these containment graphs:

6’ Fume hood containment at 60, 80, and 100 FPM:

The bottom line? This fume hood persistently shows comparable very low control levels on the ASHRAE 110-2016 test regardless of face velocity within the 60 FPM to 100 FPM range!

FINALLY, a hood that can operate at very low face velocity without diminished containment capability! Engineering and design make a difference. Engineering and design save exhaust. Engineering and design yield the lowest cost of ownership!


8 – Service and Support. This issue is really important and is underrated on the list by the rankings provided. A lab safety item like a fume hood cannot even begin its life without being “checked out” after installation to be sure it is functioning properly. One must use knowledgeable resource people who can compare how a fume hood is supposed to work with how it is actually Knowledgeable service at Flow Sciences begins with “ask Robin”. Through this contact person, a high level of service and customer support are achieved by referencing telephone questions to the appropriate engineer. This service has received the highest customer reviews. Our 800 service number is part of the fume hood label!

This may be why our best customers keep coming back with additional orders, while praising our customer service! 6


9 – Warranty.  All mechanical and electrical components of the Saf T Flow fume hood are guaranteed against defects for a period of one year from the date of receipt. A warranty form and card are included with manuals for each unit sold.

 

In addition to this rather limited issue, Flow Sciences has always “gone the extra mile” with our customers on answering questions, providing information on replacement parts, or sending out safety videos or other materials that may have been lost after the product was delivered and installed.


Summary:

 

The Flow Sciences Saf T Flow fume hood is a laboratory safety product. We have shown here how it addresses laboratory managers’ ten top criteria for a successful safety product. These fume hoods perform the tasks lab managers identify as important. They are durable, safe, easy to maintain, and ergonomically designed. They are of very high value and exhibit a very low cost of ownership compared to similar products. These fume hoods are impressively warranted to do their intended job. And Flow Sciences has an exemplary record of post-sale customer support.

 

As long as our customers keep smiling, we will keep providing the finest containment equipment in the industry!


Footnotes:

 

  1. Lab Manager Magazine, 12/2018, p57
  2. Side-by-Side Fume Hood Testing, Human-as-Mannequin Report, 2004, California Energy Commission, Sartor, Sullivan, Bell, Smith, et.al., p9
  3. On June 17, an explosion in a chemistry lab at the University of Minnesota injured graduate student Walter Partlo. He was making trimethylsilyl azide, starting with 200 g of sodium azide. The incident originated in lack of hazard awareness, school representatives say, and the department response focuses on identifying hazardous processes and communication. http://cenblog.org/the-safety-zone/2014/07/more-details-on-the-university-of-minnesota-explosion-and-response.
  4. The Fume Hood Product Life Cycle, A Cost of Ownership Analysis, Haugen, 2018, https://www.flowsciences.com/fume-hood-product-life-cycle/
  5. Typical email praise: ” I just wanted to reach out to let you know that I have dealt with many technical support and parts associates in our industry over the years and none have been more helpful or pleasant than Robin Williams. I have never been disappointed in the high quality service that Flow Sciences provides. I look forward to meeting both you and Robin at the upcoming CETA conference in Memphis.

Have a great day!”


DR. ROBERT HAUGEN
Director of Product and Technology Development

Robert K Haugen  currently designs chemical laboratory containment equipment and develops new relevant technologies for Flow Sciences Inc.in Leland, North Carolina. He has also held positions at Kewaunee Scientific, Jamestown Metal Products, and St. Charles Manufacturing in similar capacities for 31 years. Previously, he did analytical chemical work at the University of Illinois (DNA, wastewater, and crop research) and Lawrence Livermore Labs in California (nuclear weapons research).

Dr. Haugen began his career as a curriculum writer for the Illinois Office of Education, developing texts on energy, urban management, and industrial pollution topics.

He received all his degrees from the University of Illinois in Urbana-Champaign, and is currently a member of the American Society of Heating, Refrigeration, and Air Conditioning Engineers, the American Chemical Society, and the National Fire Protection Association. He has participated in the development of both ASHRAE 110-1995 and the current 2016 update.


FSI Testing Performance - Laboratory Testing Services

LELAND, NC, December 18, 2018 —Flow Sciences, Inc. (FSI) evaluates and ensures that every enclosure shipped to their customer meets all relevant standards. FSI performs procedures from the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) 110-2016 – Methods of Testing Performance of Laboratory Fume Hoods. Examples of testing procedures include flow visualization (local and large-volume challenges), tracer gas exposure modeling via human as mannequin (HAM) testing. These procedures are conducted in-house as Flow Sciences’ Factory Acceptance Testing (FAT). FAT testing is analogous to the “as manufactured” (AM) test as mentioned in ASHRAE 110-2016. Additionally, testing is conducted at the customer’s location upon request. This test is analogous to the “as installed” (AI) test. Flow Sciences, Inc. refers to this this test as the “SAT”, or Site Acceptance Test.

Aside from ASHRAE testing methodologies, Flow Sciences tests other functionalities of containment devices; one example is vibration isolation. During this test, vibration is purposefully initiated and its effect on the measurement of the balance is analyzed in accordance with Flow Sciences’ data reproducibility standards. In essence, the enclosure’s capability of isolating a balance from vibrational interferences stemming from the external environment is put to the test. Additional information regarding vibrational interferences can be found here.

For High Potency Active Pharmaceutical Ingredient (HPAPI) powder enclosures, FSI conducts surrogate powder testing to quantitatively assess containment performance. During the test, samples are collected using standard industrial hygiene field sampling methods. Following the test, samples are sent to a third-party analytical laboratory accredited by the American Industrial Hygiene Association Laboratory Accreditation Program (AIHA-LAP). Third-party IH companies can also be employed to perform the evaluation in FSI’s test facility.

For more information, please email your inquiry to info@flowsciences.com

CAMERON FAULCONER, IH-MESH
Industrial Hygienist / Product Manager

Cameron Faulconer is an Industrial Hygienist with a wide breadth of experience, spanning between commercial manufacturing, to home residences. His inspiration for his choice of career is communicating the value of preserving the health and safety of employees using the most effective and efficient means possible. Therefore, Mr. Faulconer found his place in the “Engineering Controls” rung of the hierarchy of hazard controls.

As a problem solver, Mr. Faulconer believes that the best safety solutions are created through consultative conversations with those who seek solutions. He believes communicating information derived from these conversations to be critical to the continued understanding of the toxicological impacts of the work environment.

His personal motto is “protecting the safety and health of employees from what can and cannot be seen with the naked eye”.


Performance Validation by Third Party Industrial Hygienists


Flow Sciences, a leading provider of containment solutions for laboratory, pilot plant, and manufacturing facilities consults with third party industrial hygienists to conduct in-house Factory Acceptance Tests (FATs) and Site Acceptance Tests (SATs) to ensure customers’ products perform at the level they need.

Flow Sciences partners with experienced third-party Industrial Hygiene (IH) consulting professionals from partnering companies to verify the containment performance of an enclosure using the following standardized testing methodologies:

 

  1. Surrogate Powder Testing at Flow Science’s Laboratory

 

Following IH consultation, Flow Sciences conducts personal and area air sampling inside our in-house laboratory following thorough decontamination. Air samples are run while demonstrators perform a mock task with little instruction and then submitted for AIHA Lab Accreditation Program (LAP) approved analysis. Finally, Flow Sciences’ team of scientists and engineers analyzes the resulting data and determines if the enclosure performs better than its Containment Performance Target (CPT).  Many customers choose to use their own operators and are invited to observe and participate in the testing at Flow Sciences.

 

  1. Surrogate Powder Testing at Client Site

 

If the customer requests an SAT, Flow Sciences utilizes staff from an IH company to perform the same testing methods as the FAT. However, the test is performed at the customer site. This testing option affords the customer the opportunity to verify the performance of their enclosure by having the test conducted using their own Standard Operating Procedures (SOPs) and employees.

 

  1. ASHRAE-110and ANSI/AIHA Z9.5 – Laboratory Ventilation

 

In accordance with the previously mentioned methodologies, Flow Sciences conducts Average Airflow Velocity Measurements, Flow Visualization, Large Volume Smoke, Tracer Gas, and Surrogate Gas testing. Flow Sciences utilizes consultation from IH consulting professionals to design a sampling protocol to model employee exposure in the field.

 

For more information, visit www.flowsciences.com/testing/

To view more testing results, visit www.flowsciences.com/performance/


CAMERON FAULCONER, IH-MESH
Industrial Hygienist / Product Manager

Cameron Faulconer is an Industrial Hygienist with a wide breadth of experience, spanning between commercial manufacturing, to home residences. His inspiration for his choice of career is communicating the value of preserving the health and safety of employees using the most effective and efficient means possible. Therefore, Mr. Faulconer found his place in the “Engineering Controls” rung of the hierarchy of hazard controls.

As a problem solver, Mr. Faulconer believes that the best safety solutions are created through consultative conversations with those who seek solutions. He believes communicating information derived from these conversations to be critical to the continued understanding of the toxicological impacts of the work environment.

His personal motto is “protecting the safety and health of employees from what can and cannot be seen with the naked eye”.