I have had allergies in the past, mold, grass, and other causes of hay fever, also dust and cigarette smoke.

I like getting old 8 bit systems, untested, and getting them to work. So far mostly for my own use -- but last week I bought one just for the challenge.

Unfortunately most of the systems I've obtained came in musty smelling. When I go to inspect or use them I get a reaction similar to what I get when I do household dusting (I've seen no actual mold when taking things apart).

I know that cleaning may solve the problem, and for two of them I took them apart to pieces and cleaned every inch, one system is no longer a problem, the other one I can use for an hour or so without a problem.

I have air cleaners running in the house and one right in the room where I work on these systems. I've done a lot of the cleaning outdoors, but maybe I should also do the disassembly outdoors.

I've recently read that the flame retardant in computer plastic may cause allergic reactions in some people, is it possible that given the aging of the plastic cases, that this is the problem?

Advice from anyone in similar circumstances?

I’ll accept an answer that speaks about cleaning as opposed to just filtering air.

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    Since inhalation of some particles could be the biggest problem for you, what about wearing a mask with activated carbon filtering while cleaning? They are available in different forms, some only cover your mouth and nose, others also cover your eyes.
    – DarkDust
    Commented Jun 12 at 6:51
  • 2
    @DarkDust Yes.. I have started doing that while disassembling and cleaning, my question is, what's the best way to clean as there still seems to be am issue after cleaning, and I'd like to not have to wear an n95 mask while using the systems.
    – scm
    Commented Jun 12 at 13:21
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    They didn't care much about what toxic substances went into computers back then: lead, mercury, PCBs if you go back far enough. I think GenXers have some immunity.
    – Rich
    Commented Jun 13 at 0:31
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    Flame retardant and plasticizers in the plastic of the housing and/or cables can cause major allergic reactions as well. But that is usually not by inhaling, but by skin contact. I've been playing around with computers since the early 80's and never had a problem until last November we got a new batch of patch-cables in the office and 24 hours later I started to get flaky skin on my hands. Like sun-burn, but slower progressing. Skin eventually (2 weeks) came of completely. Took 5 weeks to heal up. I have to wear gloves now, which is a real nuisance and not always possible with fine work
    – Tonny
    Commented Jun 13 at 11:25
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    @DarkDust Activated carbon is about stopping chemicals, not particles. To stop particles you want a respirator. And, yes, I have yet to find anything that bothers me that isn't blocked by one with standard P100 cartridges on it. Commented Jun 13 at 22:10

4 Answers 4


TLDR: Work outdoors, expose to sunlight, wear mask, disassemble, clean circuit boards with 90% isopropyl alcohol, clean covers with soap and water, dry completely.

I will give an answer to my question as to what I am doing with an Atari 800 that I just received. Firstly... it was an untested unit, no power supply. First thing I did was open up the box outside and put all the cardboard and packing in a recycle bin outdoors. Next I did take the chance of bringing the unit into my little workshop.

I noted some insect parts in the serial connector.. oh boy... and I plugged it in to a monitor and a power supply... it did not boot up but the light came on. I then wrestled with the top cover to get it off.. it was held down with screws and aluminum tabs, and the top seemed a bit jammed on... got it off, reseated all the cards, applied power and i did hear in the audio the typical boot up buzzing sound.. no video.

By that point I had a strong dust reaction to it, so I put it in the garage, inside a plastic garbage bag zip tied shut. to leave until I was up to it.

Today I took it out of the bag and set it up on a tray table in direct sunlight, clear day, and let it just sit in the sun for 30 minutes, with the cards exposed. took the cards out, tipped it over so the bottom was up and let it get exposed for another 20 minutes, while I washed the cards down with a spray of 91% isopropyl alcohol.

Oh, all this with an n95 mask on. Then took the screws out of the bottom cover, removed it and found lots of loose dust in there, got a handheld vacuum cleaner that I don't mind contaminating and started vacuuming.. I noted two large "dust balls" about an inch and half inch in diameter in the case... Later I realize since there were insect parts in the dust balls, that these were insect nests, but I saw no living insects... ( I did ask chat gpt about this, it's probably some spider lived in there at some point.

Done for the day, and since my vacuum battery quit before I could finish the main unit. I put it and the keyboard back sealed in the plastic bag.

After doing this I have no allergic reaction to the activity...

Next steps.. again outdoors. take the main unit apart to pieces. Wash the aluminum, top and bottom cases in soap and water, spray down the cpu board , mother board and power board in isopropyl alcohol... Oh... I have to remove every keycap and wash them in soap and water -- they have dirt on them -- probably this machine was kept in a dusty, but humid environment.

And I'll decide if I need to take the keyboard apart to pieces to clean it's components.

Then put it all back together, and on a day when I have no allergy problems, give it a test.

  • "inside a plastic garbage bag zip tied shut" -- climate depending, this can trap condensation in there. at this stage you haven't cleaned the dust out yet, so that's going to create paste that cant be blown out with air. you presumably store solvents in the garage already, so it must be ventilated-- why not leave it out on a workbench with a fan pointed at it or something? FWIW there are "hoods" for 3D printer particulate ventilation that might be useful to you both for this issue
    – Ivan
    Commented Jun 14 at 23:35
  • "it's probably some spider lived in there at some point" -- those do sound like spider egg sacs; they are all over my garage and spun by brown widows (NOT black widows, NOT brown recluses), who start biting when you mess with their young. the bite results in excruciating pain, swelling, and the bullseye rash associated with ticks and lyme disease. spiders being carriers of lyme is not supported by any literature but i ended up on antibiotics for a month having presented it to my doctor as a tick bite (despite not having been near tall grass, or even in an area known for ticks). be careful!
    – Ivan
    Commented Jun 15 at 0:07

Fast and cheap:

Aim a desk fan at your work.

The volatile exudate, if any, will be WAY concentrated in the air near your work. Dilute it into the room air, and fan-vent the room.

I should think it's better than trying to filter out the irritant when it's concentrated.

  • 3
    You'll want to aim it at your work from a moderate distance (30cm maybe?), so you get airflow rather than just turbulence.
    – wizzwizz4
    Commented Jun 12 at 18:10
  • 4
    will this reduce the problem over time? do i need to have a blower and exhaust fan whenever i use these systems?
    – scm
    Commented Jun 12 at 19:27
  • It should, assuming that a) nothing is growing in there (like mold) and b) the exhaust fan actually exhausts. Whatever is causing odor, irritation, etc. is finite in quantity otherwise, and will eventually leave the room. Commented Jun 15 at 8:11

Desktop HEPA filter fume extractors, as used for soldering, should make quite a difference. Anything that goes into them will stay there - don't forget to change the filter. If you end up doing a lot of repairs, you might want one for the flux fumes anyway. Either the sort with one big square opening or at least 2 tubes would be better than the more localised type.

If your climate is benign, a really good option is an inline (bathroom) extractor fan, with ducting from the work area to the fan, and from the fan out of an open window.

Either way, immediately after unboxing, vacuuming all the vents and joins in the case, between keys, etc. would also be good (again, using a vacuum with good filters). This will make a big difference to the amount of dust you kick up while opening the case.

With some case designs, the actual opening will cause lots of turbulent airflow. That's the bit to do with a mask, and/or outdoors, or with the extractor as close as possible.


I would guess that dust is the most likely culprit here. Even non-retro computers typically get filled with dust pretty quickly when they're running, due to the fans sucking it in. Personally, I use a small handheld vacuum cleaner with a brush on the end that's made for use with electronics and/or dust cloths to clean up the ones I'm going to work on first so that I'm not kicking up and then inhaling all of that dust while I'm trying to work on them.

Wearing an N95 dust mask, especially while doing the dusting, can also help. (Unlike for medical purposes, the kind with an outflow valve is fine for this purpose and will make it more comfortable to wear.)

  • Is there any risk of static electricity when using a vacuum cleaner? I'm less sensitive to dust, so am able to use an air duster to blow the dust to somewhere it can be safely gathered - I would be a bit wary of a vacuum cleaner close to ICs. Commented Jun 19 at 15:08
  • Good point about the outflow valve here - that can improve comfort levels considerably. Commented Jun 19 at 15:09
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    @TobySpeight They did say "that's made for use with electronics" so I assume they're referring to a vacuum that's specifically listed as ESD-safe, similar to how companies like DataVac have specific models of electric duster that are rated as ESD-safe.
    – ssokolow
    Commented Jun 19 at 22:02
  • I missed that qualifier - probably worth emphasising that most vacuum cleaners are not ESD-safe. Commented Jun 20 at 7:03

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