Summer in Japan

Summer in Japan has one drawback. Actually there are 3: it’s hot and humid. And cockroaches like that.

According to this article, there’s a new thing out which seems to work very well. Having studied chemistry, I was naturally curious what it’s active ingredient is.

Here is the product page from the manufacturer. The back of the product packaging shows the ingredients:

d.d-T Cyphenothrin it is.

Here the Wikipedia article. Very short. Has one reference to a article. I knew cockroaches are pretty sturdy, but this was new to me:

Resistance to organophosphorous and carbamate insecticides amongst German cockroaches is widely reported.

Tilak, R; Agrawal, VK; Dutta, J (2005). “Field performance of cyphenothrin: An integrated insecticide strategy against German cockroaches (Dictyoptera: Blatellidae)”. Journal of Vector Borne Diseases. 42 (2): 68–73. PMID 16161703.

To get a lot more details, have a look here from PubChem.

Important data points:

  • Very toxic for aquatic life
  • LD50 (rat) via oral: 318mg/kg, so for an average human (70kg), eating 22g has 50% chance of killing your (assuming the toxicity is same for rats and humans)
  • LD50 via skin is way higher

And here I found the d.d-T part:

TL;DR: I’ll buy one to test it out. I won’t drink it and I’ll be careful to not get this into water.

Effect on CPU Temperature by Air Temperature

It’s obvious that a lower room temperature should lower the CPU temperature. But how much does is it? Here’s the answer for a HP t620. Fanless, CPU usage 5-10%. The temperature was measured at 2 different heights: air temperature was measured about 1m above the floor, while the t620 sits about 10cm above the floor.