Not sure how I have got on this mailing list. Being from Australia I can only quote Australian Standard (AS), but if you get access (I’m sure there would be simular American ones as well) they can point you in the right direction.
· AS 2982.1 Laboratory Design and Construction; this standard tells you how to build the benches, distances between, height, etc etc
· AS 2101 Acoustic design; Tells you the noise limits and basic design (fume hoods and equipment make noise)
· AS 1668.2 Ventilation; extremely important for laboratories is having adequate ventilation in short >200m3 per hour
· AS 2243.8 Safety in Laboratories Fume Cupboards Part 8; Very important that these devices are build properily (I have come across a few American build models that don’t comply with this standard.
· AS 3846 Handling and Storage dangerous goods
· AS 1940 Storage Handling Flammable liquids
· AS 2430.3 Classification hazardous areas
· AS 4332 Cylinder storage.
To Answer your questions;
1. I would not ever use ductless hoods as first principle. There filters are really only suitable for one application at a time so if there is going to be changing applications then they will become ineffective. For basic use of Fume Cupboards (ducted) is a must. Not if using Perchlorics then this requires specialised materials and safety requirements. If there is a demonstration of a particular experiment then a ductless can be used if fitted with the filter presific for that test. The ductless come quite often all glass and can allow students to surround the hood for demonstrations. But must be fitted with the correct filter for the particular usage.
2. Any contaminant in the air is a concern, this would be a matter of what it is, and its concentration. MSDS’s will state exposure limits. If there is any doubt then within a hood it must go. All alcohols are poisons, it is the poison effect that makes you drunk when drinking Ethanol. Space can be a premium but as long as the hood in question is working properly and to standard then having 1,2,3,4,5 etc in front of it will not detract the protection it gives. There is more safety concerns from congestion
3. If the laboratories ventilation is correct and the fume cupboards are being used more there should not be any more increase of atmospheric corrosion of materials, if there is evidence of increased corrosion then the ventilation needs to be looked at, as well as what experiments are being carried out not in a fume cupboard. Just note what corrodes metals etc also corrode your lungs.
4. The standards I have quoted also have storage, standards, there must be proper segregation of chemicals. Solvents over 200L in one area may need special storage requirements. Labs always have storage problems, but in short what is in the working laboratory should be the minimum and have an external storage of bulk materials. You don’t see and mechanics workshop full of car spare parts, the same with laboratories.
5. Transport, there is more the question of manual handling issues than the materials being carried. If it can be man handled without risk then it should be fine. Solvent and acid bottles should be carried in a special bottle carrier not by hand. Gas cylinders ideally should have a special location on ground floor caged etc and the particular gases then reticulated to the locations on the other floors, Acetalyene, and Hydrogen gases have special storage requirements.
We are building a new building that will house health sciences, physics, biology, and chemistry. It will be mainly a teaching building with classrooms, teaching labs and faculty office areas. We may have a few small research areas here and there. We chemists will have the top(fourth) floor for our 6-8 teaching labs, chemical storage, and office area along with one or two small seminar/meeting rooms for around 24 people. I teach as well as do safety and so I am trying to give the best safety advice in the design as I can, but feel rather inadequate for the task. I wonder if others have some advice to offer. As we design the layouts for the rooms, certain particular questions have arisen and I was wondering what others’ experiences have been with some of the following aspects or other aspects that have not surfaced yet:
1. Are ductless hoods a reasonable choice for some/all teaching labs? I am most concerned with the great variety of materials that the organic labs use. They tend to do different experiments every time through the course and I think it might be hard to ensure the filters were always adequate. Also, other teaching labs get used for research(that uses all different materials) from time to time when lab classes are not meeting. What opinion could any of you offer on ductless hoods? Are they ultimately cost effective? Are they maintenance intensive?
2. In planning teaching labs, there is a question as to whether all the students in a lab need to be under a hood for distillations of various types or working with other materials such as silica. The introductory chemistry class lab distills mouth wash in one experiment. Does the ethanol concentration in the air pose any actual risk or the menthol? Is there some law that says exactly what should be done under a hood? Could hexane, methylene chloride, and ether be outside of a hood, for example, with enough general room ventilation and how could these be monitored to ensure safe levels in the listed standards for some chemicals? The appendix in 1910.1450 suggests 2.5 ft person for hood space, but is this done in teaching lab design when one setup is shared by two or maybe four students? Would hood bonnets be a good alternative for some things?
3. Are there some chemically resistant AV projectors that could be placed into labs. We had wanted projectors in labs before, but since other metal(locks, fume hoods, the safety shower) in the labs had become corroded it was thought that projectors would not stand up to chemical exposure? Or with a good ventilation design will this not be an issue?
4. What about storing materials in labs? Now we have a good bit of storage within the teaching labs in our old building because there is no other place for it, but from what I can tell, there are limits on in lab storage of flammables even if there are flammable cabinets.
5. What is the practice with regard to receiving chemicals and transporting them to upper floors? I am especially concerned about gas cylinders.
Thank you in advance for any opinions and experience anyone has on these topics and with these issues and perhaps other building design issues.
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