the safest thing you will probably find is a borate powder. here is a home recipe...
Roaches are never welcome guests, but that doesn't need you need to coat your home in pricey chemicals to get rid of them. Here's a homemade roach killer that will get the job done:
What You Need:
* Borax
* Sugar (granulated or powdered)
What You Do:
Mix borax and sugar together in equal parts. Then, apply it along the baseboards, in cracks, under cabinets, under the sink and anywhere else you've seen roaches. Reapply as needed until all bugs are gone.
Why This Works:
Roaches consume the mixture because they are attracted to the sugar. Once consumed, the borax damages both their digestive system and their outer skeleton, resulting in death. This works very much like the boric acid found in commerical products, but costs much less.
Benefits of Using Borax to Kill Roaches
* inexpensive
* chemical-free
* fume-free
* environmentally-friendly
Tips
1) Borax (20 Mule Team Borax) can be found in the laundry aisle at the store, since it is most commonly used as a laundry booster
2) Store any unused portions in an air-tight container to maintain freshness, and be sure to label it
3) It may be a couple of weeks before you notice a decline in the population
Warnings
1) Keep away from children and pets
2) Borax loses some of its effectiveness when it gets wet