Electric Toothbrush Gets Wet and Turns On Automatically: Safety Risks and OEM Solutions

Electric toothbrushes have become essential in modern oral-care routines, but brands still face complaints related to moisture intrusion—especially when an electric toothbrush gets wet and turns on automatically. While this seems like a small inconvenience, it can signal deeper design flaws that pose safety risks and brand-damaging reliability issues. For oral-care brands developing their next-generation device, partnering with an experienced OEM factory is critical. Below, we explore the underlying causes of moisture-triggered auto-activation and the OEM solutions that ensure durable, safe, and consistent products.

Why Electric Toothbrushes Turn On When Wet

Consumers often notice their electric toothbrush gets wet and turns on automatically after a shower or rinsing.
This issue usually stems from:

• Incomplete waterproof sealing of the power button

• Capillary water ingress near the charging port

• Low-quality PCB design with insufficient humidity protection

• Poor silicone keypad structure that temporarily bridges contacts when wet

Although the toothbrush may continue functioning, the early signs of water intrusion should never be ignored.

Hidden Safety Risks Behind Automatic Activation

An automatic turn-on event may look harmless, but the underlying safety risk is significant:

• Short circuits caused by high moisture levels

• Battery swelling or overheating in extreme cases

• Uncontrolled vibration that may cause the device to fall from surfaces

• Accelerated corrosion, shortening product lifespan

Brands must treat moisture-related malfunctions as early warning signs of a potential electrical hazard.

Engineering Weak Points OEMs Must Address

Reputable OEM manufacturers know the vulnerable zones where moisture enters:

• Button interfaces and thin-key silicone

• Junctions between shell components

• Charging base or inductive coil enclosure

• PCB solder joints lacking conformal coating

OEMs specializing in waterproof small appliances understand that durable protection must be engineered, not retrofitted.

OEM Waterproofing Solutions That Reduce Failures

High-level OEM factories apply multiple protective measures:

• IPX7–IPX8 structural design for full immersion resistance

• Double silicone sealing rings around buttons

• Hydrophobic nano-coating on PCBs for humidity & splash tolerance

• Ultrasonic welding to eliminate micro-gaps in the shell

• Vacuum leak testing during production to catch potential failures

These upgrades drastically reduce the chance that an electric toothbrush gets wet and turns on automatically during consumer use.

The Role of OEM Quality Control in Preventing Moisture Issues

Strong OEM quality control is the ultimate safeguard. Leading factories typically implement:

• Incoming material inspection (IMI) for silicone, plastics, and PCBs

• Water-resistance tests for every batch or production line

• Aging tests with high humidity exposure

• Button fatigue testing to ensure long-term structural integrity

Brands should partner with manufacturers who can document testing procedures and provide transparent QC reports.

What Brands Should Look for When Selecting an OEM Partner

When evaluating an OEM/ODM factory for electric toothbrush production, brands should prioritize:

1. Experience with IP-rated consumer electronics

2. In-house molding and waterproofing expertise

3. Compliance with international standards (CE, FCC, FDA, ISO 13485 if applicable)

4. Strong R&D team capable of improving structural and PCB designs

5. Scalable production & strict QC workflow

6. Ability to customize materials and sealing solutions

A reliable manufacturing partner ensures longevity, user safety, and stronger brand trust.

Conclusion

If an electric toothbrush gets wet and turns on automatically, it’s a clear indicator of design or manufacturing weaknesses. To prevent these failures and maintain brand reputation, oral-care companies must collaborate with OEMs that prioritize robust waterproof engineering and uncompromising OEM quality control.

By selecting the right manufacturing partner, brands can deliver safer, more durable electric toothbrushes—and differentiate themselves in an increasingly competitive market.