do fused relays ever spark?

[pow3rslave]

i've moved my charcoal canister under my front bumper, only thing is, it's right next to the two 30A fused relays that run my thermos.
i know the canister normally runs next to the battery, which i've seen make small sparks when connecting terminals and jumpers, i'm just wondering if relays ever do the same.

 

[caaf]

Relays (like any non solid-state relay) make a break connections. Under load they will spark and depending how dirty the contacts are will determine on the amount