Where Does It Say That?

Clearing up the FDA’s calibration requirements

by Jay Bucher

I’m still amazed by how many experienced, trained, professional calibration personnel do not know what the U.S. Food and Drug Administration regulations say about calibration requirements.

During my workshops and company audits, I’ve found that many professionals might not know there is a requirement, don’t know where to find it, don’t know what it actually says and, in the worst case scenario, don’t know what it means. With that in mind, I’ll clarify what the FDA says about calibration requirements, and I’ll also tell you how to meet those requirements.

Follow the code

All of the FDA requirements can be found in the Code of Federal Regulations (CFR). The specific areas that calibration professionals should be concerned with usually fall under one of these sections of 21 CFR:

  • Part 58, good laboratory practice for nonclinical laboratory studies.
  • Part 110, current good manufacturing practice (cGMP) in manufacturing, packing or holding human food equipment and utensil maintenance.
  • Part 211, cGMP for finished pharmaceuticals.
  • Part 606, cGMP for blood and blood components.
  • Part 820, cGMP that governs the methods used in—and the facilities and controls used for—the design, manufacture, packaging, labeling, storage, installation and servicing of all finished devices intended for human use.

The part that goes into the greatest detail—and in my opinion still encompasses the spirit of the other parts—is covered under 21 CFR Part 820.72, which covers inspection, measuring and test equipment:

(a) Control of inspection, measuring and test equipment. Each manufacturer shall ensure that all inspection, measuring, and test equipment, including mechanical, automated, or electronic inspection and test equipment, is suitable for its intended purposes and is capable of producing valid results. Each manufacturer shall establish and maintain procedures to ensure that equipment is routinely calibrated, inspected, checked, and maintained. The procedures shall include provisions for handling, preservation, and storage of equipment, so that its accuracy and fitness for use are maintained. These activities shall be documented.

(b) Calibration. Calibration procedures shall include specific directions and limits for accuracy and precision. When accuracy and precision limits are not met, there shall be provisions for remedial action to reestablish the limits and to evaluate whether there was any adverse effect on the device’s quality. These activities shall be documented.

(1) Calibration standards. Calibration standards used for inspection, measuring, and test equipment shall be traceable to national or international standards. If national or international standards are not practical or available, the manufacturer shall use an independent reproducible standard. If no applicable standard exists, the manufacturer shall establish and maintain an in-house standard.

(2) Calibration records. The equipment identification, calibration dates, the individual performing each calibration, and the next calibration date shall be documented. These records shall be displayed on or near each piece of equipment or shall be readily available to the personnel using such equipment and to the individuals responsible for calibrating the equipment.

A recurring theme throughout this section is the phrase "shall be documented." I can’t stress enough that if an action is taken or performed but is not documented, as far as any inspector or auditor is concerned, it did not take place.

Five steps

My calibration philosophy for meeting FDA regulations and ISO standards is simple and covers the requirements found in 21 CFR Part 820.72:

1. Say what you do. Write down the process or procedure required to calibrate on all test equipment that makes a quantitative measurement. If the item requires calibration, it also needs to be recalibrated on a regular basis.

2. Do what you say. Use the previously referenced calibration procedures. It’s not enough to go to the trouble of writing, validating, continually updating and improving your calibration procedures if you don’t use them.

I understand that in the real world—after performing dozens, hundreds or even thousands of calibrations on a particular type or model of test equipment—calibration practitioners should be able to perform the procedure in their sleep. But a couple of items come into play here.

The FDA requirements and ISO standards call for using written calibration procedures. You aren’t using a calibration procedure if that procedure is in a binder located in a different room or building and not where the actual calibration is performed.

Calibration practitioners (as well as any technician, supervisor or manager working in an FDA or ISO-regulated environment) must know where to find the information needed to perform their job and are not required to memorize any of it. They must have the procedure or work instruction needed to perform the task at hand. That means it must be in the immediate area and opened to the appropriate page.

Why is this important? It sets a good example for others who walk past. It shows new personnel that your company, department or group is in compliance with this aspect of the requirement. If there are changes to the procedure and the technicians have been trained on those changes, it is easy to follow them without relying on memory or the help of others.

Even though some tasks become so repetitive that they’re almost automatic, we are all creatures of habit. Having the appropriate calibration procedure on hand during each and every calibration is a habit we should all want.

For the record

3. Record what you did. The calibration record is one of the critical steps in the quality calibration program (QCP). Without the calibration record, which will include the as-found, as-left and standard reading from the calibration, many important aspects would be lost.

Was the test equipment within tolerance? Only by having the record can you be certain and can your supervisor (or anyone signing off as the second set of eyes) confirm the tolerances were met. When an item is found to be out of tolerance, those readings are critical in determining if there might be an impact on a product or process. That relates, in turn, to the possibility of product recall.

4. Check the results. Without the data, you can’t ensure tolerances were met, standards were not overdue to be calibrated when they were used, and the correct calibration interval and calibration dates were calculated.

5. Act on the difference. This falls under 21 CFR Part 820.72.b: "When accuracy and precision limits are not met, there shall be provisions for remedial action to reestablish the limits and to evaluate whether there was any adverse effect on the device’s quality. These activities shall be documented."

If the test equipment did not meet its tolerances, what program is in place to cover this part of the regulation? This is a double-edged sword because it also refers to your calibration standards.

When calibration equipment returns from being calibrated, what happens when it is found to have been out of tolerance while you have been using them to calibrate your company’s test equipment? Do you have a program in place to perform reverse traceability for that standard?

Can you easily identify all of the test instruments that were calibrated using out-of-tolerance standards? How much did that affect the items they were used to calibrate? Again, you need the calibration record to help make that determination.

The five aspects of a QCP are just the tip of a large iceberg in the calibration process. It is an all-encompassing program with many areas that must be covered to meet the strict regulations and standards delineated by the FDA and ISO. You must know what the requirements are if you’re going to comply with them 100%.


Jay L. Bucher is president of Bucherview Metrology Services LLC in DeForest, WI. He is editor and coauthor of The Metrology Handbook and author of several books, including Paperless Records, Ethics: The Final Frontier and Paperless Calibration Compliance for National and International Standards & Regulations. Bucher is a senior member of ASQ, the chair of the measurement quality division and a certified calibration technician.

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