Belated Happy New Year. I am finally getting caught up in my work after the holidays and death in the family. It has been a relatively warm winter so far, although we got our first snow fall this week. I hope your holidays were great and you are off to a good start this year. This column will kick off my 10th year and I hope to keep you up to date on the latest in protective clothing permeation testing methods, standards development and technical protective equipment committee meetings.
First off, I need to report on the latest information on ASTM Test Method 739-09, Standard Test Method for Permeation of Liquids and Gases Through Protective Clothing Materials Under Conditions of Continuous Contact. This is the first test method published by ASTM Committee F- 23 on Protective Clothing and it is currently being revised and updated to include a new standard reference material to replace the 16 mil neoprene used in the original round robin tests to establish required precision and bias statements. The new material being considered is Mylar, a synthetic polyester that is stable over time (does not change properties), is readily available and has been tested with acetone. It has a much longer breakthrough time than neoprene to acetone ( > 60 vs~15 min) making it more suitable for inter -laboratory testing evaluation. Committee F-23 recently met the week of January 31- February 2, 2012 in Atlanta, GA at the Hyatt Regency and has decided to use Mylar as the reference material for the inter- laboratory round robin tests. They are in the process of getting samples of Mylar, writing up a protocol and procedure for the participating laboratories to conduct the round robin test. So far there are 3 laboratories signed up to participate, including me. They hope to complete the round tests before the next F-23 Committee meeting in June. For more information on the meeting, the status of the inter-laboratory test results, and schedule of activities please check the ASTM International web site (astm.org) and click on technical committee F-23. The AIHA committee on protective equipment (PPE) plans to meet this year at the AIHA Conference in Indianapolis, IL in May where there will be professional development courses, technical presentations, panel discussions and symposiums on protective clothing. Of interest to anyone wishing to keep up to date on protective clothing in the field of industrial hygiene I would recommend that you check out the AIHA’s latest edition of the White Book, The Occupational Environment, It’s Evaluation, Control and Management, 3rd Edition (Volumes 1 and 2) that just came out at the beginning of this year. I was a co-author with Zack Mansdorf on Chapter 39 Protective Clothing. For those of you working in the field of nano technology there is an excellent chapter on nano-particles and materials that includes information on controlling exposure to nano particles in solution with gloves and disposable clothing. Currently the three standard glove materials worn are rubber, latex and neoprene.
Next, I would like to share some my personal thoughts on protective clothing and the standard methods used to evaluate performance. I have been involved in protective clothing testing, methods development and evaluation as an industrial hygiene consultant for the past eight years since retiring in 2004. Since that time I have continued to recommend, select and test clothing materials on a number of new chemicals being introduced into the workplace. Many of the chemicals have unknown toxicity and will be handled by relatively few workers and/ or researchers in a controlled environment where standard engineering controls cannot be applied. However, protective clothing (gloves and suits) is required to ensure and prevent exposure to the skin where harm, injury or illness may be caused if the chemicals permeate the skin and enter the body. By testing the chemicals useful information can be derived for preventing, protecting and controlling exposure to substances that are introduced to the environment that may be detrimental to the health, safety and well being of others. So testing is needed and will always be needed as new materials are introduced to the market and workplace. The efforts of many safety professionals and technical committees go into working on standards development so that uniform consensus can be reached. Unfortunately, even with all the data we collect on the performance of protective clothing, we will never know all the lives that have been saved or illnesses prevented. However, I have always maintained that test information on clothing is needed when it comes to safety and health issues. So I guess my motto is “test if you do not know if a protective clothing material works or have some input into developing a method to determine if it will protect”. Hopefully permeation test information can be communicated on MSDS data sheets in the future so that all workers are informed of the appropriate protective clothing to wear and that they can make their selection based on reliable data generated from standard test methods.
Finally, I would like to comment on the possibility of developing a permeation test system composed of a minimum of 4 test cells ( three each for replicate tests and 1 control) connected to an analytical device such as a gas chromatograph equipped with a flame ionization detector so that automated permeation testing could be done. A few customers have expressed interest and also need advice on setting up and assembling the permeation test cells for different applications. Depending on your needs we are interested in helping you, but need to hear from you. So please contact us for information. Hopefully, next quarter we will have information on the new reference material to be used for ASTM F739-09.
Norm Henry