egg flats that may be unsafe

[Mentat]

The issue with "dirty" cardboard is that it breeds bacteria and other pathogens. Those could affect your Dubia colony or even be passed to enclosures. Maybe you can talk to lady nicely and ask not to place shells back into egg crates. Good luck !

[Louis Charles Bruckner]

I have started using HVAC filters as egg crates in my large colonies in my 25G plastic bins.
They are really cheap and readily available in just about any size you need them,
Just don't get the ones that are coated or treated in ay way.
The least expensive ones are the best.
and the fiberglass ones won't rot or mold.

[DigitalPunk]

Also, not to be a running Josh's frog advertiser, but they do sell unused egg flats on their site for .49 cents a piece.

[Ash]

Egg Flats may harbor Salmonella and are meant as a one time usage product.

One idea is (depending on volume) to ask local cafes and restaurants to save a day or two or a weeks worth of "Clean flats" they may take care to give you non soiled ones. Some people claim to microwave or low oven cook the flats however I would not recommend this as the flats made from recycled paper can contain bits of metal that may arc in microwave or nylon that may ignite furthermore cooking them long enough to get rid of most bacteria would have to be extended as the trays are rotated and turned and this would be a fire hazard..

Drink holders are decent but I have found roaches prefer the nesting of the tight cups of eggflats and are thus better for producing young so for our Roaches there is nothing better than the large 12x12 eggflats.

Low Cost Eggflats are a find, That being said some unscrupulous sellers online will sell you relatively clean looking but used eggflats.

I know it sucks to find seemingly cheap supplies and then get socked with High shipping charges. Checkout the Reasonable Shipping. Along with Feeder Insects and Supplies Affordable Never Used Clean All Natural Compostable 12x12 EggFlats in Quantities of 1-145