Accessible Fume Hoods

[Paul Sweet]

Laboratory fume hoods often have a raised sill at the opening. Should the 34" height for an accessible fume hood be measured to the bottom of the sash opening, or to the work surface inside the fume hood?

 

[Gene Boecker]

The lab fume hood is a work space. It's not requried to meet the 34 inch height by either the ADAAG or the IBC/ANSI. That's covered under Title I of the ADA not Title III. In the ADAAG see 4.1.1(3). All they need to do is approach, enter and exit the work area. Nothing is requried to be done until an employee is hired with a disability and the a reasonable accomodation must be provided based on the specific type of disability.

In the ICC see 1103.2.3. Same thing.

 

[brudgers]

My opinion: A fume hood is typically a fixture with dedicated electrical and mechanical systems. Controls need to be accessible and the work surface needs to be accessible. So far as I recall, there are no "reach over" diagrams in the code or ADAAG...if you went by the surface and not the sill, there's no reason the sill couldn't be at 44" Aff with the surface at 34"

It's definitely not an employee work area, because employees do not enter the hood.

 

[Gene Boecker]

Sorry if I was unclear. The inside of the fume hood is not an employee work area. The space immediately in front of it is.

I agree that if possible reach ranges should be provided. But they're not required.

 

[Paul Sweet]

Sorry I forgot to mention this in my original post. These fume hoods are in a science building at a community college, and state standards require at least one in each lab to be accessible to students (in accordance with the 2004 ADAAG) even if the IBC doesn't.

 

[Gene Boecker]

Uh. . .

That makes a lot of difference.

In that case, make the work surface no higher than 34 inches AFF and controls within the reach range - nothing higher than 48 inches AFF. If the hood can have a front approach by placing it in a stand, that would be preferred. Use the knee and toe clearances. A side approach is possible if necessary due to the construction of the hood. I would suggest using a sill height not more than 38 inches based on the provisions for grocery conveyor checkouts. That is a reasonable reach over. Basically, design it like a lavatory, with a higher sill.

 

[brudgers]

Not sure why you are advocating a higher sill.

Wouldn't it just make more sense to design it like a lavatory?

Obviously, if one can be made accessible, they all can.

 

[Gene Boecker]

Agreed. The best bet would be to not have a sill. However, to address potential hazardous spills, fume hoods often have elevated sills at the front (face). If provided, the height must be limited in some manner.

 

[brudgers]

If you are interpreting the requirement as 34" to the surface inside the hood, there's no way to establish the height requirement of the sill through the code.

On the other hand, 34" sill is defensible through the code and means that the surface inside the hood will be accessible as well.

As I said there's no "reach over range." Just an obstructed forward reach and an obstructed side reach. both have a 34" max height for the obstruction.

 

[Arpit Kakkar]

Fume hood is required for the lab chemicals to prevent them from vapors, dust and gases so select best fume hood suppliers for your lab.

 

[mark handler]

http://www.locscientific.com/ada-fume-hoods
Talk to the manufacturers don't try to recreate the wheel
There are many

https://www.google.com/search?clien...owser-type&qsubts=1485860791280&action=devloc

 

[ADAguy]

Thank you Mark