FDA: Visual Inspection Inadequate for Wave Soldering Process

Electro-Tech Products, a manufacturer of transcutaneous electrical nerve stimulators, received a warning letter for quality system violations, including failure to perform installation, operation and performance qualification studies. In response to Form 483 observations, the company told the FDA it performs a visual inspection and no additional test is necessary, but the FDA said the wave soldering system is not a process that can be fully verified by inspection and must be validated, according to the July 1 warning letter, which was posted on the FDA website and then removed.
The GMP Letter