IP40 vs IP68
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP40 and IP68 are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 4 vs 6) and liquid protection (level 0 vs 8). IP40 is rated for > 1 mm — small wires and no protection, while IP68 provides dust-tight and continuous immersion (manufacturer-specified).
IP40 protects against small tools and wires (1 mm objects) but offers no water protection. Useful for indoor equipment needing finer ingress protection against small debris and tools.
IP68 is dust-tight and protects against continuous immersion in water under conditions specified by the manufacturer (typically deeper than 1 meter for prolonged periods). The standard for submersible and marine equipment.
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP40
4 — > 1 mm — Small Wires
IP68
6 — Dust-Tight
Liquid protection (second digit)
IP40
0 — No Protection
IP68
8 — Continuous Immersion (manufacturer-specified)
Dust-tight
IP40
No
IP68
Yes
Water-jet resistant
IP40
No
IP68
Yes
Submersible
IP40
No
IP68
Yes
Outdoor suitable
IP40
No
IP68
Yes
The exact difference (IP40 vs IP68)
Solid protection
IP40
Level 4 — > 1 mm — Small Wires
IP68
Level 6 — Dust-Tight
IP40 provides "> 1 mm — Small Wires" (level 4), while IP68 provides "Dust-Tight" (level 6). IP68 is 2 levels higher.
Liquid protection
IP40
Level 0 — No Protection
IP68
Level 8 — Continuous Immersion (manufacturer-specified)
IP40 provides "No Protection" (level 0), while IP68 provides "Continuous Immersion (manufacturer-specified)" (level 8). IP68 is 8 levels higher.
NEMA equivalents
No direct NEMA equivalent.
Recommendation
IP68 offers higher overall protection than IP40. Choose IP68 for harsher environments; IP40 may suffice for milder conditions and can be more cost-effective.