IP33 vs IP21
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP33 and IP21 are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 3 vs 2) and liquid protection (level 3 vs 1). IP33 is rated for > 2.5 mm — tool / wire and spraying water (up to 60°), while IP21 provides > 12.5 mm — finger and vertically dripping water.
IP33 protects against tools and 2.5 mm objects plus spraying water up to 60° from vertical. A practical rating for indoor equipment subject to light spray or for sheltered outdoor fixtures.
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)
IP33
3 — > 2.5 mm — Tool / Wire
IP21
2 — > 12.5 mm — Finger
Liquid protection (second digit)
IP33
3 — Spraying Water (up to 60°)
IP21
1 — Vertically Dripping Water
Dust-tight
IP33
No
IP21
No
Water-jet resistant
IP33
No
IP21
No
Submersible
IP33
No
IP21
No
Outdoor suitable
IP33
No
IP21
No
The exact difference (IP33 vs IP21)
Solid protection
IP33
Level 3 — > 2.5 mm — Tool / Wire
IP21
Level 2 — > 12.5 mm — Finger
IP33 provides "> 2.5 mm — Tool / Wire" (level 3), while IP21 provides "> 12.5 mm — Finger" (level 2). IP33 is 1 level higher.
Liquid protection
IP33
Level 3 — Spraying Water (up to 60°)
IP21
Level 1 — Vertically Dripping Water
IP33 handles 80 kPa (tube) / 50 kPa (nozzle) (Spraying Water (up to 60°)), while IP21 handles 0.1 mm/min drip rate (Vertically Dripping Water). IP33 provides 2 levels more liquid protection.
NEMA equivalents
No direct NEMA equivalent.
Recommendation
IP33 offers higher overall protection than IP21. Choose IP33 for harsher environments; IP21 may suffice for milder conditions and can be more cost-effective.