hey please be careful with 3d printed whistles. they can be cool and useful but the gaps from layer lines and stuff can allow spit to get trapped and build up and breed harmful bacteria. you really shouldn't be using these more than once, and throw them away when you've used them (preferably, you should recycle them). hot water can help clean them if you're super worried but ideally you should be using injection molded plastic whistles.
Thanks for thinking about safety! Hopefully it won't surprise you to know that we thought about this, and we definitely advise that everybody wash anything that they put in their mouths repeatedly, whether it's a fork or a whistle.
The above links to a peer-reviewed paper published by the Institute of Electrical and Electronics Engineers and given at an IEEE conference.
tl;dr: with the same kind of washing with soap and water that you would use on any other utensil or item you would put into your mouth, these whistles will retain no more bacteria than any other plastic item, and certainly less than the cutting board you've owned for 10 years. They do not retain more bacteria than injection-molded items.
Anywhere bacteria can get, soapy water can get, too, and if you're concerned about biofilm, you can use baking soda or steritabs (the kind used by food service, which we keep at home to clean our water bottle caps and straws) for extra safety.
Reasonable caution is always warranted, but these items are safe for regular use as long as they are cleaned as you would any item you put in your mouth over and over.
Thank you for this opportunity to set people's minds at ease with science!
Don't forget, kinderlach:
Most forms of 3D printer filament are heat-safe up to or over 100 degrees Celsius.
Which means they can be boiled.
If you're worried you can't get to every area or you're disabled in a way that makes small items difficult (I see you, my peeps with Parkinson's/arthritis/CP/EDS), you can throw that sucker in a pan of boiling water for three minutes. Fish it out with a fork and it'll be hot enough to dry completely by evaporation in just a minute or two, and it'll also be sterilized.
@nerdykeppie I don't know what kind of filament you use, so it may be worth test-boiling one of the whistles to make sure I'm not advising everyone to melt their safety tool, but this is what I do with stuff like metal straws and it works great.
Please don't boil these whistles. They will melt. The glass transition temperature for this filament is 85°C. If you wish to be extra careful about bacteria on these whistles, please use the information laid out in our previous response on this post. While cleaning with soap and hot water as you would clean your dishes should be sufficient—and if you don't have particularly nimble fingers, putting a few drops of soap in a jar with hot water, closing it securely, and shaking the shit out of it will do the trick very nicely—Steramine sanitizing tablets are an appropriate additional line of defense. This is the tool used in food service for sanitizing all food prep surfaces and dishware, and is what Spider has previously posted about using to regularly sanitize his water bottles and lids.
The linked bottle will allow you to sanitize whatever can soak in a gallon of hot water once a week for almost 3 years at a cost of $.092 per week. Your whistles and water bottle lids plus any other important items should fit in a gallon of water, and $.092 per week should be an accessible price point for the vast majority of people.
Use whatever source you prefer for them; I'm linking Amazon for ease of explanation.
You can also rinse with baking soda in water and then clean water if concerned about biofilm.
We use PETG filament for these whistles; this is the generally recommended filament type for food contact. Other filament types are either just slightly more liable to harbor bacteria or contain styrene and are thus not recommended for putting in your mouth.
Here is a link to the safety information for the company whose filaments we use for this project:
Q: Do your pigments contain heavy metals such as lead and other toxic products?
A: All of our pigments come from a major US color lab, they are non toxic & ROHS compliant. While our raw PETG and PLA resin is approved for food contact , we are not a FDA approved facility nor is the final filament product FDA approved.
To address one of the other common scare "facts" which we have seen: no, you will not get measurable amounts of lead in you from the brass nozzles used on 3D printers. You get more lead on and in you by picking up a brass key once than you could ever get by using a 3D whistle a hundred times.
EDIT: @apocalycious has supplied the additional information that all of the nozzles on her machines are steel or tungsten carbide anyway so the lead is literally zero.
