IP45 vs IP21
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP45 and IP21 are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 4 vs 2) and liquid protection (level 5 vs 1). IP45 is rated for > 1 mm — small wires and water jets (6.3 mm nozzle), while IP21 provides > 12.5 mm — finger and vertically dripping water.
IP45 protects against 1 mm solid objects and low-pressure water jets (6.3 mm nozzle, 30 kPa). A mid-range indoor/outdoor-covered rating for equipment that may be rinsed or hosed gently.
Designed for environments requiring protection against solid objects larger than 12.5 mm and protection against vertically falling drops of water. Dripping water shall have no harmful effects., IP21 is an IEC 60529 code combining solid level 2 with liquid level 1.
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP45
4 — > 1 mm — Small Wires
IP21
2 — > 12.5 mm — Finger
Liquid protection (second digit)
IP45
5 — Water Jets (6.3 mm nozzle)
IP21
1 — Vertically Dripping Water
Dust-tight
IP45
No
IP21
No
Water-jet resistant
IP45
Yes
IP21
No
Submersible
IP45
No
IP21
No
Outdoor suitable
IP45
Yes
IP21
No
The exact difference (IP45 vs IP21)
Solid protection
IP45
Level 4 — > 1 mm — Small Wires
IP21
Level 2 — > 12.5 mm — Finger
IP45 provides "> 1 mm — Small Wires" (level 4), while IP21 provides "> 12.5 mm — Finger" (level 2). IP45 is 2 levels higher.
Liquid protection
IP45
Level 5 — Water Jets (6.3 mm nozzle)
IP21
Level 1 — Vertically Dripping Water
IP45 handles 30 kPa (Water Jets (6.3 mm nozzle)), while IP21 handles 0.1 mm/min drip rate (Vertically Dripping Water). IP45 provides 4 levels more liquid protection.
NEMA equivalents
Recommendation
IP45 offers higher overall protection than IP21. Choose IP45 for harsher environments; IP21 may suffice for milder conditions and can be more cost-effective.