IP21 vs IP55
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP21 and IP55 are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 2 vs 5) and liquid protection (level 1 vs 5). IP21 is rated for > 12.5 mm — finger and vertically dripping water, while IP55 provides dust-protected and water jets (6.3 mm nozzle).
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.
IP55 is dust-protected and resists low-pressure water jets (6.3 mm nozzle, 30 kPa). A popular industrial rating for equipment exposed to dust and directed water spray but not immersion.
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP21
2 — > 12.5 mm — Finger
IP55
5 — Dust-Protected
Liquid protection (second digit)
IP21
1 — Vertically Dripping Water
IP55
5 — Water Jets (6.3 mm nozzle)
Dust-tight
IP21
No
IP55
Limited
Water-jet resistant
IP21
No
IP55
Yes
Submersible
IP21
No
IP55
No
Outdoor suitable
IP21
No
IP55
Yes
The exact difference (IP21 vs IP55)
Solid protection
IP21
Level 2 — > 12.5 mm — Finger
IP55
Level 5 — Dust-Protected
IP21 provides "> 12.5 mm — Finger" (level 2), while IP55 provides "Dust-Protected" (level 5). IP55 is 3 levels higher.
Liquid protection
IP21
Level 1 — Vertically Dripping Water
IP55
Level 5 — Water Jets (6.3 mm nozzle)
IP21 handles 0.1 mm/min drip rate (Vertically Dripping Water), while IP55 handles 30 kPa (Water Jets (6.3 mm nozzle)). IP55 provides 4 levels more liquid protection.
NEMA equivalents
No direct NEMA equivalent.
Recommendation
IP55 offers higher overall protection than IP21. Choose IP55 for harsher environments; IP21 may suffice for milder conditions and can be more cost-effective.