ALONG came a spider and a woman with insect spray - and what followed was that the washing machine the spider ran under blew up, the windows blew out and the woman was injured.

Police say the 66-year-old woman spotted the spider on the washing machine of her Kirribilli home about 1pm on Saturday.

She opted for insecticide and sprayed the spider, which ran under the machine.

The woman pursued the spider, sprayed under the machine and it exploded. The blast blew out the kitchen and bathroom windows and destroyed the washing machine.

Fire investigators believe the motor of the washing machine ignited the insect spray, triggering the explosion.

The woman suffered blurred vision and singed hair, and was treated at the scene by paramedics.

There was no sign of the spider, police say.

AAP