IP ratings, or Ingress Protection ratings, are standardized classifications that define the degree of protection provided by electrical enclosures and equipment against the intrusion of solid objects (like dust and dirt) and moisture (such as water). The IP rating system is internationally recognized and defined by the International Electrotechnical Commission (IEC) in standard IEC 60529.

The IP rating consists of the letters "IP" followed by two digits. Each digit represents a specific aspect of protection as follows:

1. First Digit (Protection against Solid Objects):

   • 0: No protection.
   • 1: Protection against solid objects greater than 50 mm (e.g., hands or large tools).
   • 2: Protection against solid objects greater than 12.5 mm (e.g., fingers).
   • 3: Protection against solid objects greater than 2.5 mm (e.g., tools and thick wires).
   • 4: Protection against solid objects greater than 1 mm (e.g., wires, screws).
   • 5: Dust protected. Ingress of dust is not entirely prevented but does not interfere with the satisfactory operation of the equipment.
   • 6: Dust-tight. Complete protection against dust.

2. Second Digit (Protection against Moisture):

   • 0: No protection.
   • 1: Protection against vertically falling water droplets (condensation).
   • 2: Protection against water droplets at an angle of up to 15 degrees from vertical.
   • 3: Protection against spraying water at an angle of up to 60 degrees from vertical.
   • 4: Protection against splashing water from any direction.
   • 5: Protection against low-pressure jets of water from any direction.
   • 6: Protection against high-pressure jets of water from any direction.
   • 7: Protection against temporary immersion in water up to 1 meter deep for 30 minutes.
   • 8: Protection against continuous immersion in water under specified conditions.

For example, an IP65 rating indicates that the equipment is dust-tight (first digit 6) and protected against low-pressure water jets from any direction (second digit 5).

IP ratings are commonly used to specify the environmental protection of electrical devices, such as outdoor lighting fixtures, electrical enclosures, industrial equipment, and consumer electronics, ensuring that they can operate safely and reliably in different environmental conditions.