Summer is here and the year is half over. Today is July 1st and it’s time to write my third column for this year. The ASTM Committee F23 on Protective Clothing and Equipment met in Denver, Colorado last week and I am waiting to review copies of their minutes to update you on their activities. The AIHA Protective Clothing and Equipment Committee had their meeting in Minneapolis, Minnesota early in June. They had a productive meeting that focused on updating the Chapter on Protective Clothing in the Industrial Hygiene White Book. Another item of concern that was discussed was protective clothing barriers to nano-particles. NIOSH has done a considerable amount of work in identifying and evaluating nano-particle hazards in the work environment, but still is looking at developing analytical methods to measure their concentration. Without reliable analytical methods, you can not develop protective clothing test methods to measure penetration or permeation of nano-particles. Because of the size, nano-particles are thought to be more hazardous and toxic since they can be inhaled deeper in the lungs and penetrate the skin more readily. Currently, there is a lot of collaborative research and development going on in this country and internationally on nano-technology standards and guidelines for protecting workers and preventing exposures. Just this month the US house of Representatives passed a bill to reauthorize the National Nanotechnology Initiative (NNI) – H.R. 5940 to strengthen nanotechnology safety research to ensure a plan is developed for environmental health and safety.
Since I do not have much to report on in terms of updates to protective clothing test methods and performance, I thought I would share some recent experience testing protective clothing materials for a client. The client requested permeation tests on 20 different clothing materials to two chemicals used at manufacturing and research facilities in this country and abroad. The analytical method used to detect these two chemicals was very sensitive (ppb range) and caused decontamination problems with the ASTM 1 inch glass permeation test cells that I was using, particularly if the chemical broke though the clothing material and contaminated the collection chamber side of the cell. In order to decontaminate the cells, both the challenge and collection chambers, I had to thoroughly rinse them individually in alcohol, wash them separately in soap and water, then rinse at least three times in water before starting each test. Before I started the next tests I checked the water collection medium for the chemicals to assure that there was no detectable chemical at time zero. It was a challenge to make sure that the cells were clean and assemble 12 cells a day to test three materials in triplicate (including a control) for 8 hours and start up the next day to do another round of tests. Although time consuming, this procedure worked well to clean and decontaminate the cells. Another thought that I had was simply to connect each of the test cell collection chambers in series and pump a continuous flow of water through them for a period of time or simply put, dilute until no detectable amount was found.
Well so much for my experience in testing protective clothing materials. Do you have any experiences to share or are you in need of consultation? Please give Rich Pesce or I a call or e-mail us to let us know if we can help. Enjoy the rest of the summer.