In Singapore, cockroaches are impossible to completely eradicate due to the tropical climate which is ideal for cockroaches. In many other countries, a common method to kill cockroaches is using Boric Acid. Boric acid is considered a natural substance, and is effective at killing cockroaches. It works as a “stomach poison affecting the insects’ metabolism, and the dry powder is abrasive to the insects’ exoskeletons”. As such, it is impossible to develop a “resistance” to boric acid, unlike for insecticides where numerous cockroaches are now immune to insecticides.
Boric acid is also considered non-toxic, it is similar to table salt in its toxicity level. Boric acid has a “secondary kill” effect: cockroaches who die will be eaten by other cockroaches, leading to a chain reaction of cockroach deaths. Hence, it is more effective than sprays or traps which only kill the cockroach that is targeted.
However, when one starts to look for boric acid in Singapore, it is quite hard to find it in the pure powder form. Whether it is banned, or is simply not popular, it seems that no one on the internet knows.
I found a cockroach bait containing Boric Acid in Qoo10 below. It is a Malaysian brand. It is written on the packaging that boric acid is the active ingredient, and I also double confirmed with their Facebook customer service. Here it is:
Cockroach from HDB Rubbish Chute
Another problem about old HDB estates is the interior rubbish chute. Though very convenient, it is also a direct pathway for cockroaches to enter your home. The solution is to install a new air-tight rubbish chute hopper such that the cockroaches cannot pass through.