Ingress Protection
IP stands for Ingress Protection, and is an international standard measurement of how well an electrical enclosure can keep out “foreign bodies” — in this case, dirt, dust and water.
IP ratings are displayed as the letters ‘IP’ followed by two numbers, each one of which has a meaning. The first number is the level of protection from dust and debris, the second is the level of protection from moisture. Simple as that.
IP67 versus IP68
Common values that you’ll see here on light bars and driving lights are IP67 and IP68. IP67 means that the light is dustproof and capable of withstanding water immersion up to 1m deep for 30 minutes.
The difference with IP68 is that is capable of withstanding water immersion up to 3m deep for 30 minutes.
In practice, we don’t expect your 4WD to be 3 metres under-water for over 30 minutes (we hope not anyway!), so a rating of IP67 is more than enough. Something to double-check here though is that the lights will be able to sustain pressure washers at close range. Look out to see if the manufacturers have a disclaimer against this, as many do.
Another factor to keep in mind when submerging your lights is temperature. Crossing a river when your lights are hot can cause aluminium housings to contract and allow water to enter through the seals. Even if this doesn’t happen, condensation can be a problem, despite a lamp being totally watertight.
