Home Infomercial THMG098a – DuPont Brings Us Chemical Protective Suits Explained

THMG098a – DuPont Brings Us Chemical Protective Suits Explained

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In this extra episode, we chat with DuPont resident expert Dan Bowen. We discuss how DuPont chemical protective suits are tested, which standards they’re tested to, and why. Take a listen to this is a very informative episode on PPE.

Complete Show Notes

0:45 Introduction to Dan Bowen

  • Technical specialist for DuPont Protection Technologies – supports end users of their protective apparel products
  • Works with both industrial users and first responders for every type of suit they make
  • He covers all of North America and is basically the field geek for supporting the product lines

2:15 How Are DuPont’s Garments Chemically Tested?

  • They use actual chemical testing to evaluate the performance of the materials
  • Penetration testing
    • Visual only test that works well for closures, seams, and zippers
    • Helps you determine whether the suit can keep out dirty water
    • Challenge material is put in contact with the suit and lab technicians then take a look at the other side of the suit to see if the material is coming through
    • Problematic because you can’t see vapors coming through or trace amounts of dangerous liquids
  • Permeation testing
    • Put a challenge material in contact with material in question, and some sort of monitor is put on the other side – much more scientific
  • DuPont doesn’t do their own testing – instead, they use independent third-party laboratories
  • Testing procedure
    • Start a stopwatch as soon as the chemical comes into contact with the material
    • Report the number of minutes it takes for the chemical to be sensed as it comes through the material at a tenth of a microgram per square centimeter
    • As soon as they hit that threshold, the stopwatch is stopped
    • They report the number of minutes it took that chemical to come through that particular fabric at that concentration
    • Testing is stopped at 8 hours
  • DuPont has their own permeation database – symbols include:
    • IMM (immediate) – any permeation less than 10 minutes
    • Number between IMM and 480 minutes – they’ll report the actual number of minutes
    • Greater than 480 minutes – means the chemical didn’t come through the fabric within 8 hours

7:00 How Does DuPont Decide Which Chemicals to Test?

  • Chemical Abstract Library (CAL) lists over 100 million chemicals
  • Each chemical test runs from hundreds to thousands of dollars, so they can’t test everything
  • DuPont’s permeation database contains test data for the most common chemicals we come into contact with – sulfuric acid, nitric acid, phosphoric acid, ammonium, etc.
  • Database may not have the exact chemical you’re looking for, but chances are it has permeation data on a substance that’s pretty close to the one you’re dealing with – i.e. hexane and oxygen
  • It’s important to have information on the class and subclass of the substance you’re handling when you go to use the database

10:50 How Do They Determine When a Chemical is Too Strong for the Suit?

  • In the U.S., the tenth of one microgram per square centimeter figure from before is what’s reported
  • In Europe, it’s one microgram per square centimeter
  • Make sure you’re looking at the right permeation data to ensure you’re comparing apples to apples

12:10 How Do Concentration and Temperature Affect Suit Permeation?

  • They may have data for a range of concentrations in the permeation database for both liquids and vapors
  • Phase changes have to be taken into account since substances are most concentrated when they’re liquids because their molecules are closer together
  • You also have to think about working strengths of chemicals – database also has information for these since people may buy full-strength chemicals and then dilute them
  • If you have a concentration that’s lower than the concentration in the database, you can trust the database – if it’s higher, you can’t trust the database
  • For every 10 degrees Celsius the temperature increases, permeation time is essentially cut in half
  • Database also includes a range of temperatures they’ve tested certain chemicals at
  • Remember that if a chemical gets hot enough, it can actually melt the surface of the suit (rather than permeating it)

20:25 Is it Safe to Reuse Suits?

  • DuPont uses MUSE (Multiple Use, Single Exposure) as a guideline – safe to reuse garments as long as they weren’t exposed to anything
  • Encapsulated Level A suits are extremely expensive ($1,500-$3,500), so a lot of people are tempted to reuse them
  • DuPont recommends against reusing Level A for several reasons
    • Decon isn’t designed to neutralize substances – it’s designed to make it safe for us to exit our suits
    • We have no guarantee that whatever we’re using to decon the suit can make it safely reusable
    • Permeation starts the minute the material comes into contact with the fabric – this means we have no way of knowing whether it can still perform as well when it did when it was brand new
    • Incompatibles are also an issue – this can be problematic if two incompatibles come into contact with one another on the suit
  • Don’t get rid of your Level A, though – you may be able to use it for training or other purposes depending on its condition
  • DuPont offers a lot of different training suits you can use

28:15 Ways to Demonstrate the Differences Between Penetration and Permeation

  • Oil of wintergreen in a plastic baggie or Ouzo liqueur and a butyl glove – two everyday examples
  • You won’t smell anything at first, but you will in a few minutes because the substances have permeated into the baggie and glove
  • Same thing goes for two-stroke engine mix – baggie doesn’t dissolve, but the material comes right through the walls very quickly
  • You can’t stop permeation, which is why DuPont recommends that you should never reuse a Level A

33:05 More Information

  • Contact Dan via email: Dan Bowen
  • Check out DuPont’s SafeSPEC® program – also available as an app for iPhone and Android
    • Includes permeation database
    • Lost of videos on how to don and doff
    • Whitepapers on a variety of topic
  • There’s a “Contact Us” form on the SafeSPEC® site
  • DuPont also provides a ton of free resources and sample suits
  • They also put out a quarterly newsletter called The Glow Worm for the hazmat community

Have a question? Send an email to feedback@thehazmatguys.com or leave a message on our Haz Mat Guys comment hotline: 843-628-1484

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