[labnetwork] Cleanroom dB levels

Mon Jun 16 15:07:39 EDT 2025

Loop earbuds are generally fantastic and great hearing protection. They're
much less disruptive to hearing outside noise than the standard foam
earplugs we all use whenever we're next to a vacuum pump tool for more than
a short period. If you're not using hearing protection in an area with
densely packed vacuum pumps then you should start today. Protection should
be applied before you brush up against OSHA limits. We sit below 80dB in
most places but I still put loops in when I'm in the lab for more than 30
minutes. You get through your first decade as a vacuum systems engineer and
you can feel your hearing change behavior, regardless of if you get
medically tested. Wear your earplugs.

As far as earbud use for audio goes in a cleanroom - that's a long and
detailed conversation that is facility specific. I would encourage anyone
to carefully understand whether they're trying to enforce a cultural rule
via a safety standard. Cultural rules are also reasonable! But know why
your rules are in place, because once something is a safety rule you have
an extremely high bar to change the policy. Most practical outcomes I've
seen are that earbuds aren't allowed but no one is likely walking around
checking under the bouffant caps.

My personal opinion - If you have a "safety" rule that everyone's quietly
violating when it's inconvenient (whenever someone's waiting for a 20
minute vacuum pumpdown with nothing to do), you have leak in the boundary
conditions of your safety culture. What else aren't they doing when it's
inconvenient? Institutional authority is a currency of trust and it should
be spent carefully. Design your rules with that in mind.

-Ryan

On Sun, Jun 15, 2025 at 4:39 PM Kevin Owen <kowen at andrew.cmu.edu> wrote:

> Everything's a slippery slope... Bone conduction headphones definitely
> allow you to hear your surroundings well while still listening to music (I
> own a pair and can confirm), but you'd probably need to turn the volume
> insanely high to hear over the cleanroom background noise. Also that volume
> makes your whole face buzz... Standard foam earplugs are great for
> dampening all sounds, but that also includes people yelling from the next
> bay. My personal preference when I'm working with users is noise cancelling
> earbuds with no music; I can actually hear voices better with standard
> noise cancelling than with just passive noise suppression, or without
> anything and having to hear them over the screaming pumps. I also recently
> got a pair of Loop Engage
> <https://www.loopearplugs.com/products/engage-plus> earplugs and they
> work very well in the cleanroom (even with the mutes in). Not exactly
> something to "stock" in your gown room, but you could recommend it to users
> looking for ear protection. And I don't care what OSHA says, 70 dB is
> insanely loud. Even an hour bare-ears is enough to aggravate my tinnitus
> for the rest of the day and likely trigger a migraine. At the end of the
> day, it's just another example of that not-so-common thing they call
> "common sense".
>
> -Kevin
>
> On Fri, Jun 13, 2025 at 6:43 PM Kyle Keenan <kckeenan at seas.upenn.edu>
> wrote:
>
>> Hi Justin,
>>
>> In my opinion, this is a slippery slope. I would imagine that even bone
>> conduction earphones could be turned up loud enough in a 70 dB ambient
>> noise environment that you would not hear someone yelling for help in a
>> neighboring area of the lab. I could also envision a situation where
>> someone handling chemicals is startled by another person because they did
>> not hear them coming. If you allow this kind of thing, you know there will
>> be those who will misunderstand, or pretend they misunderstand, and will
>> use traditional earbuds which may be noise-cancelling. To me, it's not
>> worth the risk and the liability. If you want to have a meeting or listen
>> to music, I think you should leave the lab.
>>
>> One guy's two cents.
>>
>> Best,
>> Kyle
>>
>> On Fri, Jun 13, 2025 at 10:29 AM Justin C Wirth <jcwirth at purdue.edu>
>> wrote:
>>
>>> This is a bit of a tangent, but on the earbud/headphone issue, I’ve
>>> started informally recommending to our users and staff that if they want to
>>> listen to music or have meetings in the cleanroom, to use bone conduction
>>> headphones such as these: https://shokz.com/
>>> <https://urldefense.com/v3/__https://shokz.com/__;!!IBzWLUs!TWIS8GmaRycewEN10kU1_IWlhfxRRwYioQjNeWKvV7Lm2rCyokkt5Mh8ENU_QnA_ly0AVFIsKJMfm5t1t72d3b4$>
>>> (there are also cheaper knock-offs/off-brands on Amazon).
>>>
>>>
>>>
>>> They don’t go in your ears at all, they sit on your temple and transmit
>>> sound through that way. This keeps your ear canals open to hear ambient
>>> sounds like alarms and anyone yelling for help, but also lets you listen to
>>> a Zoom/Teams meeting or music or whatever. These ARE NOT noise cancelling
>>> so won’t help reduce the sound of the cleanroom itself, but have worked as
>>> a very good compromise between the desire to be able to listen to something
>>> in the cleanroom but also still be able to be alert to sounds in the lab.
>>>
>>>
>>>
>>> Thanks,
>>>
>>> Justin
>>>
>>>
>>>
>>> Justin C. Wirth, PhD
>>>
>>> Senior Research Engineer – EBL Processes & Nanofab Process Consultation
>>>
>>> Birck Nanotechnology Center | Room 2287A
>>> 765.494.8203 | jcwirth at purdue.edu
>>>
>>> BNCWiki
>>> <https://urldefense.com/v3/__https://purdue.atlassian.net/wiki/spaces/BNCWiki__;!!IBzWLUs!TWIS8GmaRycewEN10kU1_IWlhfxRRwYioQjNeWKvV7Lm2rCyokkt5Mh8ENU_QnA_ly0AVFIsKJMfm5t1Qtr6GLY$>
>>> | Purdue iLab
>>> <https://urldefense.com/v3/__https://purdue.ilabsolutions.com/__;!!IBzWLUs!TWIS8GmaRycewEN10kU1_IWlhfxRRwYioQjNeWKvV7Lm2rCyokkt5Mh8ENU_QnA_ly0AVFIsKJMfm5t1uecGlFI$>
>>> | Book time on my calendar
>>> <https://urldefense.com/v3/__https://outlook.office.com/bookwithme/user/5ad94572a9c04a4e8aa9159479128868@purdue.edu?anonymous&ep=plink__;!!IBzWLUs!TWIS8GmaRycewEN10kU1_IWlhfxRRwYioQjNeWKvV7Lm2rCyokkt5Mh8ENU_QnA_ly0AVFIsKJMfm5t10sTg2b0$>
>>>
>>>
>>>
>>> *From:* labnetwork <labnetwork-bounces at mtl.mit.edu> * On Behalf Of *Kyle
>>> Keenan
>>> *Sent:* Wednesday, March 19, 2025 2:55 PM
>>> *To:* Massey, Travis <massey21 at llnl.gov>
>>> *Cc:* labnetwork at mtl.mit.edu
>>> *Subject:* Re: [labnetwork] Cleanroom dB levels
>>>
>>>
>>>
>>> ---- *External Email*: Use caution with attachments, links, or sharing
>>> data ----
>>>
>>>
>>>
>>> For what it's worth, we tell people no earbuds whatsoever, with the two
>>> main arguments being that you might not hear a tool alarm or, worse,
>>> someone yelling for help in another bay.
>>>
>>>
>>>
>>> Our lab also has ambient noise levels of 70-75 dB.
>>>
>>>
>>>
>>> Kyle
>>>
>>>
>>>
>>> On Wed, Mar 19, 2025 at 2:43 PM Massey, Travis <massey21 at llnl.gov>
>>> wrote:
>>>
>>> We found the same thing in a very similar setup and identical ES&H
>>> guidance.  Typically, we see 70-75 dB in the absence of personnel.  The
>>> chase is closer to 75 dBa, and the bays are closer to 70 dBa.  There were a
>>> few addressable offenders, like a loud spot where disrupted airflow created
>>> significant turbulence, increasing sound levels to 75 dBa in the cleanroom,
>>> but this was easily resolved by removing the obstruction.  Because none of
>>> these exceed the 85 dBA for 8h limit, ES&H will not get involved.
>>>
>>>
>>>
>>> Users concerned about sound levels were tentative about hearing
>>> protection.  What they *actually* wanted in raising the concern was (a)
>>> to address the handful of loud spots, and (b) approval to use their noise
>>> cancelling earbuds in the cleanroom.  To the latter, we’re in a trial
>>> period – if it doesn’t impact our ability to get someone’s attention and
>>> talk with them when needed (e.g., can switch into transparency mode for a
>>> conversation), then neither I nor ES&H mind terribly if they wear their
>>> earbuds.  Quality of life counts for something.  We only cautioned that
>>> *if* they play music, they set volume limits to not damage their
>>> hearing.
>>>
>>>
>>>
>>> *From:* labnetwork <labnetwork-bounces at mtl.mit.edu> *On Behalf Of *N
>>> Shane Patrick
>>> *Sent:* Tuesday, March 18, 2025 5:41 PM
>>> *To:* Joseph Losby <joseph.losby at ucalgary.ca>
>>> *Cc:* labnetwork at mtl.mit.edu
>>> *Subject:* Re: [labnetwork] Cleanroom dB levels
>>>
>>>
>>>
>>> Our facility is bay and chase, no subfab, so all the pumps and chillers
>>> and all are right next door to the equipment. After a recent request by one
>>> of our staff members, I did an informal survey using NIOSH’s Sound Level
>>> Monitor app (NIOSH SLM) and an uncalibrated microphone. The only time I got
>>> above 80db was when people were talking or dropped things, even in our
>>> loudest chases.
>>>
>>>
>>>
>>> Sustained levels at 85 or more are the levels of concern for hearing
>>> loss according to US agencies. Our EHS team agreed with me that even with
>>> an uncalibrated system we were very unlikely to reach sustained levels of
>>> concern. People are still welcome to use hearing protection for their own
>>> comfort, of course, and I’d likely provide it for my staff if asked, but it
>>> takes a lot to get to that sustained 85db point.
>>>
>>>
>>>
>>> Now, 80db acoustics and the associated mechanical vibrations from all of
>>> that is certainly enough to mess with sensitive instruments, and we have
>>> had to relocate certain tools or just accept our environmental noise
>>> translates to measurement noise. That’s more a matter of design and space
>>> limitations for us than anything else.
>>>
>>>
>>>
>>> -N. Shane Patrick
>>>
>>> Manager, Lab Operations and Safety
>>>
>>> Washington Nanofabrication Facility
>>>
>>>
>>>
>>>
>>>
>>> Sent from my iPhone
>>>
>>>
>>>
>>> On Mar 18, 2025, at 5:26 PM, Joseph Losby <joseph.losby at ucalgary.ca>
>>> wrote:
>>>
>>> 
>>>
>>> Hi everyone,
>>>
>>>
>>>
>>> Have any of you taken acoustic noise measurements of your cleanroom
>>> facilities, or have a basis of design for acceptable levels?
>>>
>>>
>>>
>>> If you can share your facility ACH with noise level ( dB ) that would be
>>> great.  Any other input will be much appreciated as well.
>>>
>>>
>>>
>>> Cheers,
>>>
>>> Joe
>>>
>>>
>>>
>>>
>>>
>>> *Joseph Losby, PhD*
>>>
>>> *Manager, qLab Operations*
>>>
>>> *joseph.losby at ucalgary.ca <joseph.losby at ucalgary.ca>*
>>>
>>>
>>>
>>> <Outlook-3jbzrxwq.jpg>
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>>>
>>>
>>>
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>>>
>>>
>>> --
>>>
>>> Kyle Keenan
>>>
>>>
>>>
>>> Senior Manager - Laboratory Operations
>>>
>>> Quattrone Nanofabrication Facility
>>>
>>> University of Pennsylvania
>>>
>>> P: 215-898-7560
>>>
>>> F: 215-573-4925
>>>
>>
>>
>> --
>> Kyle Keenan
>>
>> Senior Manager - Laboratory Operations
>> Quattrone Nanofabrication Facility
>> University of Pennsylvania
>> P: 215-898-7560
>> F: 215-573-4925
>>
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