[doc30]

There are a lot of issues to address in the first post. Emphasis should always be on lab safety, even with chemicals with minimal hazards on a daily basis. It is very easy to get lazy with the low hazard materials and carry such lax safety habits to more dangerous materials.

In addition to common sense use of chemicals, there is this beast called OSHA that has the authority to enforce safety laws and that includes organic chemistry labs. If there are violations and someone does get hurt, OSHA will come in and can shut down the lab until it complies with safety requirements and/or find somebody to arrest. If you manage a lab and tell someone to ignore safety and they get hurt, it is a criminal offence in the U.S.

I know from experience that research chemists can be the most difficult people to get to comply with safety laws because they think they have an education that elevates them above safety specifications. That doesn't help when one is fighting for his or her life in the hospital, or is sitting in jail because they thought they knew what they were doing and got somebody else hurt. I have lost friends, one a post doc, to completely preventable accidents. What do you tell his wife and newborn daughter after an acetone recovery bottle on a bench was contaminated, ignited and caused burns over 80% of his body and he suffered for 2 weeks in a hospital before dying?

Make sure you follow the appropriate and required safety precautions when working with chemicals. Make sure you have the right engineering controls in place and that they are working properly. Follow the MSDS. Different chemicals require different PPE. Nitrile gloves don't protect against ketones, for example. There are legal limits to how much flammable solvent can be out on a bench. And there are legal limits to how many flammable cabinets can be in a single room. Three are legal limits to how much halogenated solvent can be in the air in the room.

Dose, as others have said, makes the poison. But do not neglect the cumulative effect of low level exposure over a long time period. The information on MSDS's represents the current knowledge of the material. Acetone is not a nice chemical and has those properties listed above by others.

A cavalier attitude towards chemical safety gets people killed. You may be working in a lab everyday of your life and you owe it to yourself, your colleagues, your friends and your family to make sure everyone goes home everyday and that nothing in the lab will keep them from seeing their grandchildren in the future.

[orgopete]

I had posted in another thread about safety. I am not wishing to antigonize anyone with my opinions along those lines. However, I do have a question about what seems to be is issue in this thread. The original poster was concerned about minimizing all possible exposures. There has been some discussion about the severity or necessity or operating in a middle ground of accepting some level of exposure.

There are a lot of issues to address in the first post. Emphasis should always be on lab safety, even with chemicals with minimal hazards on a daily basis. It is very easy to get lazy with the low hazard materials and carry such lax safety habits to more dangerous materials.

… I have lost friends, one a post doc, to completely preventable accidents. …

Make sure you follow the appropriate and required safety precautions when working with chemicals. … Follow the MSDS. Different chemicals require different PPE. Nitrile gloves don't protect against ketones, for example. There are legal limits to how much flammable solvent can be out on a bench. And there are legal limits to how many flammable cabinets can be in a single room. Three are legal limits to how much halogenated solvent can be in the air in the room.

Dose, as others have said, makes the poison. But do not neglect the cumulative effect of low level exposure over a long time period. …

I feel this post is implying that a low level chemical exposure and a death are causally related. Perhaps the poster could correct me if my condensation of the post has altered the meaning of the post and to describe the manner in which the accident occurred.

My experience suggests that accidents pose a greater risk than low levels of exposure (depending on the chemicals). I am not advocating that it is okay to swim in a bathtub of acetone or any other common chemical. Organic chemicals always possess a danger that is similar to gas in the house or flour in a flour mill. I don't know of anyone being directly injured by a low level exposure to methane or flour, yet they can be lethal.

[doc30]

I had posted in another thread about safety. I am not wishing to antigonize anyone with my opinions along those lines. However, I do have a question about what seems to be is issue in this thread. The original poster was concerned about minimizing all possible exposures. There has been some discussion about the severity or necessity or operating in a middle ground of accepting some level of exposure.

I feel this post is implying that a low level chemical exposure and a death are causally related. Perhaps the poster could correct me if my condensation of the post has altered the meaning of the post and to describe the manner in which the accident occurred.

My experience suggests that accidents pose a greater risk than low levels of exposure (depending on the chemicals). I am not advocating that it is okay to swim in a bathtub of acetone or any other common chemical. Organic chemicals always possess a danger that is similar to gas in the house or flour in a flour mill. I don't know of anyone being directly injured by a low level exposure to methane or flour, yet they can be lethal.

I understand your differentiation between lab accidents and protection from chemical exposure. Both are important pillars in laboratory safety, but there is a fair amount of overlap. From personal experience, people either have overall good safety habits or they don't. Slopiness in one area often extends into the other.

Hence, the first line of defense against chemical exposure, either acute or chromic, are appropriate and effective engineering controls. The second line of defense are good administrative procedures and training regarding chemical handling. The very last line of defense is PPE. If there is low level, chronic chemical exposure, it is necessary to make sure the airborn concentration is maintained below legal limits, depending on one's jurisdiction. For a research lab, and this is just my opinion, there needs to be increased sensitivity to chronic exposure because the biological effects of many of the materials are unknown. With today's technology, there is no reason proper ventilation cannot be engineered into laboratories and storage systems installed that do not vent into to lab.

To your specific point, low level chemical exposure in the lab can cause serious health effects. What is written on an MSDS as a hazard is there because it is a known effect, not a hypothetical argument. There is plenty of precident where low level, chronic expsosures have caused health problems, and, as you mentioned, depend largely on the chemicals involved. But it also depends on the individual and their sensitivity. I have worked with people that have become sensitized to acrylics from low level, chronic exposure. One wiff of fumes in the lab and he becomes covered in bright red rashes. Isocyanates, a common material used in bulk to make polyurethanes, has caused pulmonary problems from low level, airborn exposure. One other person I know lost a percentage of lung function from that because they had an unusually high sensitivity to that material and the airborn concentration was below legal limits. When I was a grad student, there was one professor that allegedly developed an allergy to platinum!

One of the administrative controls that I personally do not like where I'm at is that we have to maintain an annual list of all the chemicals I've handled and sign off saying I've read and understood the MSDS. It's a pain to have to do, but my employer does it to protect themselves from liability and can state that we were provided the information on how to safely handle the chemical.

I am aware that many chemists see it as a necessity that they will experience chemical exposure during their careers. However, that does not excuse them from trying to prevent exposure nor from cutting corners for the sake of an experiment. It also does not absolve their supervisors and their facilities from legal liability should chemical exposure cause health problems.