Tag Archives: maintenance

control the room environment

Environmental Controls: The Basics

By Vince Sebald, Vince Sebald
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control the room environment

The outside environment can vary widely depending on where your facility is located. However, the internal environment around any activity can have an effect on that activity and any personnel performing the activity, whether that’s storage, manufacturing, testing, office work, etc. These effects can, in turn, affect the product of such activities. Environmental control strategies aim to ensure that the environment supports efforts to keep product quality high in a manner that is economical and sensible, regardless of the outside weather conditions.

For this article, let us define the “environment” as characteristics related to the room air in which an activity is performed, setting aside construction and procedural conditions that may also affect the activity. Also, let us leave the issue of managing toxins or potent compounds for another time (as well as lighting, noise, vibration, air flow, differential pressures, etc). The intent here is to focus on the basics: temperature, humidity and a little bit on particulate counts.

Temperature and humidity are key because a non-suitable environment can result in the following problems:

  • Operator discomfort
  • Increased operator error
  • Difficulty in managing products (e.g. powders, capsules, etc)
  • Particulate generation
  • Degradation of raw materials
  • Product contamination
  • Product degradation
  • Microbial and mold growth
  • Excessive static

USP <659> “Packaging and Storage Requirements” identifies room temperature as 20-25°C (68-77 °F) and is often used as a guideline for operations. If gowning is required, the temperature may be reduced to improve operator comfort. This is a good guide for human working areas. For areas that require other specific temperatures (e.g. refrigerated storage for raw materials), the temperature of the area should be set to those requirements.

Humidity can affect activities at the high end by allowing mold growth and at the low end by increasing static. Some products (or packaging materials) are hydroscopic, and will take on water from a humid environment. Working with particular products (e.g. powders) can also drive the requirement for better humidity control, since some powders become difficult to manage in either high or low humidity environments. For human operations without other constraints, a typical range for desirable humidity is in the range of 20 to 70% RH in manufacturing areas, allowing for occasional excursions above. As in the case of temperature, other requirements may dictate a different range.

control the room environment
In some cases, a locally controlled environment is a good option to reduce the need to control the room environment as tightly or to protect the operator.

In a typical work environment, it is often sufficient to control the temperature, while allowing the relative humidity to vary. If the humidity does not exceed the limits for the activity, then this approach is preferred, because controlling humidity adds a level of complexity (and cost) to the air handling. If humidity control is required, it can be managed by adding moisture via various humidification systems, or cooling/reheating air to remove moisture. When very low humidity is required, special equipment such as a desiccant system may be required. It should be noted that although you can save money by not implementing humidity control at the beginning, retrofitting your system for humidity control at a later time can be expensive and require a shutdown of the facility.

Good engineering practice can help prevent issues that may be caused by activities performed in inappropriately controlled environments. The following steps can help manage the process:

  • Plan your operations throughout your facility, taking into account the requirements for the temperature and humidity in each area and know what activities are most sensitive to the environment. Plans can change, so plan for contingencies whenever possible.
  • Write down your requirements in a User Requirement Specification (URS) to a level of detail that is sufficient for you to test against once the system is built. This should include specific temperature and RH ranges. You may have additional requirements. Don’t forget to include requirements for instrumentation that will allow you to monitor the temperature and RH of critical areas. This instrumentation should be calibrated.
  • Solicit and select proposals for work based on the URS that you have generated. The contractor will understand the weather in the area and can ensure that the system can meet your requirements. A good contractor can also further assist with other topics that are not within the scope of this article (particulates, differential pressures, managing heating or humidity generating equipment effects, etc).
  • Once work is completed, verify correct operation using the calibrated instrumentation provided, and make sure you add periodic calibration of critical equipment, as well as maintenance of your mechanical system(s), to your calibration and maintenance schedules, to keep everything running smoothly.

The main point is if you plan your facility and know your requirements, then you can avoid significant problems down the road as your company grows and activity in various areas increases. Chances are that a typical facility may not meet your particular requirements, and finding that out after you are operational can take away from your vacation time and peace of mind. Consider the environment, its good business!

VinceSebald

Maintenance and Calibration: Your Customers Are Worth It!

By Vince Sebald, Vince Sebald
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VinceSebald

Ultimately, the goal of any good company is to take care of their customers by providing a quality product at a competitive price. You take the time to use good practices in sourcing raw materials, processing, testing and packaging to make sure you have a great final product. Yet in practice, sometimes the product can degrade over time, or you find yourself facing costly manufacturing stoppages and repairs due to downed equipment or instrumentation. This can harm your company’s reputation and result in real, negative effects on your bottom line.

One thing you can do to prevent this problem is to have a properly scaled calibration and maintenance program for your organization.

First, a short discussion of terms:

Balance Calibration
Figure 1– Periodic calibration of an electronic balance performed using traceable standard weights helps to ensure that the balance remains within acceptable operating ranges during use and helps identify problems.

Calibration, in the context of this article, refers to the comparison of the unit under test (your equipment) to a standard value that is known to be accurate. Equipment readings often drift over time due to various reasons and may also be affected by damage to the equipment. Periodic calibration allows the user to determine if the unit under test (UUT) is sufficiently accurate to continue using it. In some cases, the UUT may require adjustment or may not be adjustable and should no longer be used.

Maintenance, in the context of this article, refers to work performed to maximize the performance of equipment and support a long life span for the equipment. This may include lubrication, adjustments, replacement of worn parts, etc. This is intended to extend the usable life of the equipment and the consistency of the quality of the work performed by the equipment.

There are several elements to putting together such a program that can help you to direct your resources where they will have the greatest benefit. The following are some key ingredients for a solid program:

Keep it Simple: The key is to scale it to your operation. Focus on the most important items if resources are strained. A simple program that is followed and that you can defend is much better than a program where you can never catch up.

Written Program: Your calibration and maintenance programs should be written and they should be approved by quality assurance (QA). Any program should include the following: 

  • Equipment Assessment and Identification: Assess each piece of equipment or instrument to determine if it is important enough to be calibrated and/or requires maintenance. You will probably find much of your instrumentation is not used for a critical purpose and can be designated as non-calibrated. Each item should have an ID assigned to allow tracking of the maintenance and/or calibration status.
  • Scheduling System: There needs to be some way to schedule when equipment is due for calibration or maintenance. This way it is easy to stay on top of it. A good scheduling system will pay for itself over time and be easy to use and maintain. A web-based system is a good choice for small to mid-sized companies.
  • Calibration Tolerance Assignment: If you decide to calibrate an instrument, consider what kind of accuracy you actually need from the equipment/instrument. This is a separate discussion on its own, but common rule of thumb is that the instrument should be at least 4 times more accurate than your specification. For very important instruments, it may require spending the money to get a better device.
  • Calibration and Maintenance Interval Assignments: Consider what interval you are going to perform maintenance for each equipment item. Manufacturer recommendations are based on certain conditions. If you use the equipment more or less often than “normal” use, consider adjusting the interval between calibrations or maintenance. 
  • OOT Management: If you do get an Out of Tolerance (OOT) result during a calibration and you find that the instrument isn’t as accurate as you need. Congratulations! You just kept it from getting worse. Review the history and see if this may have had an effect since the last passing calibration, adjust or replace the instrument, take any other necessary corrective actions, and keep it up.

    Maintenance with Checklist
    Figure 2- Maintenance engineers help keep your systems running smoothly and within specification for a long, trouble-free life.
  • Training: Make sure personnel that use the equipment are trained on its use and not to use equipment that is not calibrated for critical measurements. Also, anyone performing calibration and/or maintenance should be qualified to do so. It is best to put a program in place as soon as you start acquiring significant equipment so that you can keep things running smoothly, avoid costly repairs and quality control problems. Don’t fall into the trap of assuming equipment will keep running just because it has run flawlessly for months or years. There are many bad results that can come of mismanaged calibration and/or maintenance including the following:
  • Unscheduled Downtime/Damage/Repairs: A critical piece of equipment goes down. Production stops, and you are forced to schedule repairs as soon as possible. You pay premium prices for parts and labor, because it is an urgent need. Some parts may have long lead times, or not be available. You may suffer reputational costs with customers waiting for delivery. Some calibration issues could potentially affect operator safety as well.
  • Out of Specification Product: Quality control may indicate that product is not maintaining its historically high quality. If you have no calibration and maintenance program in place, tracking down the problem is even more difficult because you don’t have confidence in the readings that may be indicating that there is a problem.
  • Root Cause Analysis: Suppose you find product that is out of specification and you are trying to determine the cause. If there is no calibration and maintenance program in place, it is far more difficult to pinpoint changes that may have affected your production system. This can cause a very significant impact on your ability to correct the problem and regain your historical quality standards of production.

A solid calibration and maintenance program can go a long way to keeping your production lines and quality testing “boring”, without any surprises or suspense, and can allow you to put more sophisticated quality control systems in place. Alternatively, an inappropriate system can bog you down with paperwork, delays, unpredictable performance, and a host of other problems. Take care of your equipment and relax, knowing your customers will be happy with the consistent quality that they have become accustomed to.