What are the 4 types of quality control?

The 4 types of quality control are systematic methods used to monitor, evaluate, and maintain product quality throughout pharmaceutical, biotechnology, medical device, and supplement manufacturing processes. Quality control (QC) is a core component of GMP-regulated operations and supports compliance with FDA, EMA, ISO, and ICH quality standards by identifying defects, contamination risks, and process variability before product release.

The four primary types of quality control include:

1. Process Control — Monitors manufacturing operations in real time to ensure processes remain within validated specifications and operational limits.
2. Acceptance Sampling — Evaluates representative product samples from a batch to determine whether the entire lot meets predefined quality standards.
3. Control Charts — Uses statistical monitoring tools to track process performance, identify trends, and detect deviations or instability during production.
4. Product Quality Inspections — Involves laboratory testing, visual inspections, microbiological analysis, and analytical verification of raw materials, intermediates, and finished products.

These quality control methods are widely implemented across CDMOs, CROs, sterile manufacturing facilities, biologics production plants, and QA/QC laboratories. Regulatory agencies such as the FDA and EMA routinely assess QC systems during inspections to verify data integrity, validated analytical methods, environmental monitoring controls, and batch release procedures. Effective quality control programs support contamination prevention, supply chain reliability, audit readiness, and consistent product quality in highly regulated healthcare manufacturing environments.