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Data Centre Cleaning

New International Data Centre Cleanliness Standard

Cleaning computer rooms is probably not high on a facility manager’s priority list but it should be! Are you aware that an international standard exists for cleanliness levels in data centres? Meeting the ISO 14644 standard is easy when data centre cleaning is planned, implemented according to a schedule, and routinely audited to ensure its effectiveness.

With the proliferation of cloud computing, managed services and co-location, customers want a guarantee that the environment which houses their critical data or equipment is clean enough not to pose a risk to their operation. The International Standards Organisation developed ISO 14644-1 Classification of Air Cleanliness in 1999. Though not a specific computer environment standard, ISO 14644 applies to cleanrooms and “associated controlled environments”. Increasingly, the IT industry considers data centres to be controlled environments and has begun referencing ISO 14644. Demonstrating compliance to this standard assures yourself and others that you are applying industry best practices to your IT environment.

ISO 14644 Standard

This standard started in the cleanroom industry, but what exactly is a cleanroom? It is a special environment, typically used in manufacturing or scientific research, which has low levels of environmental pollutants such as dust, airborne microbes, aerosol particles and chemical vapours. More accurately, a cleanroom has a controlled level of contamination. Contamination cannot be totally eliminated, only reduced. Controlling contamination starts with specifying how much of it exists in a given environment, then taking steps to minimise it. ISO 14644 states contamination levels as the maximum number of particles per cubic metre of air in six distinct sizes. Particles sizes range from 0.1 to 5 microns. To put that in perspective, the average human hair is 50 microns. Nine ISO cleanliness classes exist based on particle thresholds. Cleanrooms operate at different classes of cleanliness depending on what their purpose is. The lower the ISO Class, the fewer particles in the room and, consequently, the cleaner the room is. Most Australian cleanrooms like those used in medical device manufacturing or the aerospace industry are ISO Class 5 to 9.

Cleanroom vs. Data Centre

Data centres are now being treated like ISO Class 9 and sometimes even ISO Class 8 controlled environments. They have several key similarities to cleanrooms. Both types of facilities control temperature, humidity, air flow and who enters the room. However, major differences exist which affect the ability of computer facilities to achieve ISO Class 8/9 cleanliness levels. Data centres are neither designed, nor built to be this clean. They are not constructed from specially selected materials which shed minimal particles. They are not easily cleaned, having many areas where dust can accumulate. People do not wear protective garments, gloves and facemasks when working inside them. No controls are placed on items and their packaging which are brought into and sometimes stored inside data centres. Computer room air conditioning (CRAC) units cannot remove particles down to sub-micron levels. Cleanrooms rely on High-Efficiency Particulate Air (HEPA) filtration to remove 99.97% of all particles greater than 0.3 microns from the air that passes through them. The net result is uncontrolled particle levels in the data centre.

How to achieve the standard

Incorporating cleanroom standards into data centre facility maintenance can benefit not only cleanliness levels, but also operational reliability. However, ISO 14644 has no section devoted to cleaning. The standard only provides particle number limits to quantify how clean an environment is. No mention is made of how to reach these levels. Cleanroom methodology needs to be applied to the IT environment. Cleanrooms operate using very strict protocols found in a written Scope of Works (SOW). A SOW for a data centre must be created to achieve similar results.

  • First, assess the needs of the facility. What areas require cleaning? All data centres are not the same, but most have sub-floors of various depths containing cables and sensors, above-floor areas in different configurations, server racks and pods housing the most critical equipment, high-rise fixtures suspended from a slab or a ceiling void with dropped panels, and support areas such as UPS and plant rooms.
  • Each area requires a different cleaning method. Specialised equipment and procedures remove contaminants without spreading them around or introducing new ones. A list should specify what equipment and chemicals are to be used in each area, with Material Safety Data Sheets (MSDS) for each chemical kept on file. Exact methods documented in writing instruct the cleaner not to disturb circuit breakers, switches and cabling connections when cleaning adjacent areas. Completing a Job Safety Analysis (JSA) ensures proper observance of Work Health and Safety practices.
  • Who is responsible for carrying out the procedures? How well do you know your cleaners? Have they passed criminal background checks? Are they security-cleared to the correct level for the room? Do they complete, sign and date a checklist of cleaning tasks performed, adding comments on anything out of the ordinary? What ongoing training do they receive to enhance their understanding of the environment?
  • Frequency and timing of cleaning are also critical. The number of people entering the room has a dramatic effect on its cleanliness, as do construction or maintenance activities which generate particles. Is there a firm schedule of cleaning with future dates? Do periods of reduced activity occur which might be suitable for major cleans?
  • Include risk assessments to weigh up the likelihood and impact certain events such as construction and maintenance may have on the data centre. Review room security, escorting protocols and the list of people granted access to determine who else is tracking in contaminants.
  • Disaster response and recovery should also be part of the cleaning SOW. Do you have a wet/dry vacuum on stand-by to rapidly remove water in the event of a flood? Are unnecessary boxes being stored inside the computer room which pose a fire hazard?
  • All the above items should be fully documented with revision numbers and put in a manual. These documents need to be reviewed annually to make certain they continue to meet the needs of the room and get updated as changes occur.

Controlling the process

Audits must be performed on a routine basis to ensure cleaning is effective. A list of Key Performance Indicators (KPIs) relevant to the SOW forms the basis of an audit checklist. Review any comments such as “water stain under CRAC unit” on the cleaners’ checklist to pick up any changes before they become problems. Perform visual and white-glove inspections to gauge visible particle levels. Because the unaided human eye can see only down to about 40 microns, indoor air quality (IAQ) testing is the only way to monitor “invisible” particles of the sizes covered by ISO 14644. It can be easily accomplished with a handheld device and is a useful diagnostic tool. Equivalent to validation in the cleanroom industry, IAQ testing gives some indication of cleaning effectiveness. If particles are not being removed from the room and continue to accumulate, then an air quality report can show this. Cleaning is not the only reason air quality can suffer. Increasing particle levels can be an early indicator of air quality problems such as improperly filtered fresh air, breakdown products from CRAC unit belts, poor sealing of the room, circulation of builders’ dust never removed from room, and particles coming from redundant equipment and boxes stored in the room. As part of your quality management plan, take initial readings to establish a baseline, then schedule a time once a year to retest and detect any changes in the air quality. Test reports provide documented, time-stamped evidence on compliance to the ISO 14644 standard and can be shown to potential clients and internal customers.

In recent times the goal posts have moved. The IT industry has changed dramatically with online access to stored data required 24/7. Downtime is not acceptable. Cleaning is more critical than ever. The manager who is ultimately responsible for the uptime and service delivery of the data centre needs to have the cleaning regimen under control.

Submit your details to access and download a copy of “10 Step Plan to Meeting ISO 14644-1 Particle Standards in a Data Centre”.

Written by Bob Allan and Caroline Wright of BACS Contamination Control


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