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States of matter
States of matter CH&S Netways
A
s safety professionals, we have a strong tendency to look at the composition of materials, and human behaviors. We are mostly concerned about how a given chemical may react with other materials, or may be ingested, or have properties that may harm human tissue. We also look at behavior, i.e. how someone may be handling a material, storing materials or using materials. But, we have a tendency to forget that the state of the material may have a huge impact on the potential hazards. For vapors and mists, particularly with hydrocarbons; we have been conditioned to think of respiratory protection and potential explosive hazards. But there are other state of matter hazards that are lurking out there and many you may not be considering. For example, liquid hazards, yes water, coffee, soda, etc. all have a potential hazard. We think of slip, trips and falls if a walking surface is wet. Additionally, there are the electric hazards associated with the liquid contacting the surface, and potential electrical hazards associated with pouring a liquid. Remember, bonding and grounding???? Additionally, some liquids are cryogenic – liquid nitrogen, argon, helium, etc. These present temperature hazards. And, what about a liquid rapidly changing state??? (This is the issue with natural gases and ice ball formations.) What about solids? We tend to think of things in a solid form as pretty stable. Yet, we have a number of examples where the solids are probably less stable than liquid forms, picric acid for one. However, there is a solid hazard out there that we encounter every day and OSHA and EPA even has a number of standards for it. Additionally, in certain situations we may take precautions but most of the time we do not even think about it. What is it? Dust. Over the past year, parts of Oklahoma, Texas and New Mexico have been in a severe drought. This has produced a number of dust storms. Some of the more spectacular ones were on the news in Arizona. When these storms approach, the news or weather anchor persons have provided a number of tips and
1871-5532/$36.00 doi:10.1016/j.jchas.2012.01.007
precautions that the general public should take: Avoid outdoor activity. If you must go outside spend as little time outside as possible Avoid vigorous exercise, especially if you have asthma or a breathing-related condition Stay indoors, with windows and doors closed Stay in air-conditioned premises, if possible and ensure regular maintenance of air conditioner filters. But there are some more subtle consequences of the drought that have brought the issue of dust to the forefront. These include: dusty hay, grain dust, crustal materials, and ash. The air in areas hardest hit by the drought is filled with tons of material. We have seen grain silo explosions, and fires that are quickly started by the smallest spark or static because of the amount of dust in the air. It is not just the farms or agriculture that is impacted. The amount of dust that accumulates inside buildings is also huge, covering desks, computers, storage areas, etc. with a fine layer of material. But it is just dirt, right? And unless you have asthma or a breathing-related condition what is the problem? Well, there are still numerous health concerns. Respirable dust is defined as particles small enough to penetrate the nose and the upper respiratory system. The concern is that these particles are too small to be expelled by the body’s natural defense mechanisms. The particle size break point, i.e. the point where dust can reach the lungs, is at approximately 10 mm (hence, the EPA standards for PM10 – Particulate Matter). As you might imagine, there are lots of things out there that may be less than 10 mm. Coal dusts, asbestos, silcias, etc. are the well known hazards. But, there are others. So the next time you clean out that storage room. Think of the hidden hazards as well and do a proper safety evaluation. If personal protective equipment is needed make sure that you do all of the proper prerequisite training and evaluations prior to putting someone in jeopardy.
ß Division of Chemical Health and Safety of the American Chemical Society Elsevier Inc. All rights reserved.
41
A
s safety professionals, we have a strong tendency to look at the composition of materials, and human behaviors. We are mostly concerned about how a given chemical may react with other materials, or may be ingested, or have properties that may harm human tissue. We also look at behavior, i.e. how someone may be handling a material, storing materials or using materials. But, we have a tendency to forget that the state of the material may have a huge impact on the potential hazards. For vapors and mists, particularly with hydrocarbons; we have been conditioned to think of respiratory protection and potential explosive hazards. But there are other state of matter hazards that are lurking out there and many you may not be considering. For example, liquid hazards, yes water, coffee, soda, etc. all have a potential hazard. We think of slip, trips and falls if a walking surface is wet. Additionally, there are the electric hazards associated with the liquid contacting the surface, and potential electrical hazards associated with pouring a liquid. Remember, bonding and grounding???? Additionally, some liquids are cryogenic – liquid nitrogen, argon, helium, etc. These present temperature hazards. And, what about a liquid rapidly changing state??? (This is the issue with natural gases and ice ball formations.) What about solids? We tend to think of things in a solid form as pretty stable. Yet, we have a number of examples where the solids are probably less stable than liquid forms, picric acid for one. However, there is a solid hazard out there that we encounter every day and OSHA and EPA even has a number of standards for it. Additionally, in certain situations we may take precautions but most of the time we do not even think about it. What is it? Dust. Over the past year, parts of Oklahoma, Texas and New Mexico have been in a severe drought. This has produced a number of dust storms. Some of the more spectacular ones were on the news in Arizona. When these storms approach, the news or weather anchor persons have provided a number of tips and
1871-5532/$36.00 doi:10.1016/j.jchas.2012.01.007
precautions that the general public should take: Avoid outdoor activity. If you must go outside spend as little time outside as possible Avoid vigorous exercise, especially if you have asthma or a breathing-related condition Stay indoors, with windows and doors closed Stay in air-conditioned premises, if possible and ensure regular maintenance of air conditioner filters. But there are some more subtle consequences of the drought that have brought the issue of dust to the forefront. These include: dusty hay, grain dust, crustal materials, and ash. The air in areas hardest hit by the drought is filled with tons of material. We have seen grain silo explosions, and fires that are quickly started by the smallest spark or static because of the amount of dust in the air. It is not just the farms or agriculture that is impacted. The amount of dust that accumulates inside buildings is also huge, covering desks, computers, storage areas, etc. with a fine layer of material. But it is just dirt, right? And unless you have asthma or a breathing-related condition what is the problem? Well, there are still numerous health concerns. Respirable dust is defined as particles small enough to penetrate the nose and the upper respiratory system. The concern is that these particles are too small to be expelled by the body’s natural defense mechanisms. The particle size break point, i.e. the point where dust can reach the lungs, is at approximately 10 mm (hence, the EPA standards for PM10 – Particulate Matter). As you might imagine, there are lots of things out there that may be less than 10 mm. Coal dusts, asbestos, silcias, etc. are the well known hazards. But, there are others. So the next time you clean out that storage room. Think of the hidden hazards as well and do a proper safety evaluation. If personal protective equipment is needed make sure that you do all of the proper prerequisite training and evaluations prior to putting someone in jeopardy.
ß Division of Chemical Health and Safety of the American Chemical Society Elsevier Inc. All rights reserved.
41