Smell of petrol from shower drain

[illiterato]

This afternoon I suddenly got a really strong smell of petrol ( definitely not gas) downstairs. Tracked it down to the drain of the ground floor shower room which is windowless. Ran the shower for 10 mins, opened all the windows and the smell has disappeared but what could have caused it? Any ideas? It wasn’t the normal sulphury/ fatty drains smell ( we do get niffy drains so used to that). It was a very definite smell of petrol. I just can’t think what’s caused it and also if I should be worried. TIA.

*farty drains smell

Do you have oil heating, possibly a leak if so?

One of your neighbours was pouring petrol in their drain either outside or inside and your trap under the shower was dry, so the smell came straight in.
They shouldn't pour petrol in the drain as it's a pollutant, they should take it to the dump in a sealed container, but I doubt many people do that.
Some people use petrol as a degreaser for engine or bike parts.

@snowflakeinastorm no- we don’t have an oil heater, generator or burn any solid fuel. Just bog standard, mains supplied gas and electric. But the smell is definitely petrol, not domestic gas.

@johnd2 that’s what I was thinking. I’ve run the shower in there for 20 mins and left the extractor fan on overnight and the smell has gone so will see if it comes back. I guess I might have to get the drains flushed.

Found a few threads after I posted with same issue after neighbours have spilt petrol in their house or gardens.

We had exactly the same thing OP and the fire brigade came out with sniffing gear. Turned out it was someone on the road behind (we live on a hill) tipping something down a drain and the fumes came up through all the drains downhill of it.

Thanks @SpaceNambo. I was wondering who I should actually call if it didn’t go away. Good to know it should be the fire brigade. It’s has gone now so think someone must’ve just done that uphill from us.