Cleanroom laundries have a standard operating procedure (SOP) for all cleanroom garments that are pocessed through their facility. Garments are segregated by type (coverall, hood, boots, frocks), by customer and by soil. They are cleanroom washed using an appropriate wash formula for the contaminants and particles of concern, and dried in a dryer equipped with HEPA or ULPA filters. Garments are then tested, inspected and folded, usually under Class 10 (ISO4) primary air, individually packaged, hermetically sealed and returned to the customer. Many laundries will designate a lot number to the batch of garments as they are processed. The lot number might be provided to the customer on a document accompanying the shipment that also reflects the results of the QA test used for lot acceptance. This does little to help the customer identify the lot the garments were processed in once they are separated from the documentation. Ideally the lot number would be printed on each individual package as well.
Lot numbers on each package of cleanroom clothing can be extremely beneficial to the end user. When a garment is taken out of a package and there appears to be a problem with it you know would have effected every garment in the batch process, then having the packages each identified with their lot number makes it real handy to pull only those garments you know are effected. Also, if the end user asks for a change in garment processing, such as the addition or elimination of a softener, it is easy to tell by the lot number identifications which garments were processed before and after the change.
If a wearer finds a non-conformance, such as the garment is still damp, in disrepair, or stained, they can provide that lot number to the uniform service supplier to assist in the investigation and hasten corrective action. If the end user suspects that garments may be contributing to high particle counts in their room, providing the lot nmber identification to the supplier will allow them to provide you with the data surrounding the batch processing of those garments. This might include critical criteria such as wash temperatures and chemicals, what other garments were processed with yours, cleanroom HVAC gauge readings, and garment test results.
Lastly, the lot numbers are extremely helpful in inventory control. People who are responsibe for setting up the garment packages in a change area should rotate the inventories for first in, first out use. This would help make certain all inventories receive the same amount of wear and washings over time. The lot numbers also help to determine how well the inventories are being used. When inventories are used most efficiently, lot numbers would only be 3-5 weeks old by the time the garment is worn. If packaged garments in your inventory have lot nmbers that are 20-50 weeks old, you have more garments than you need. If the lot numbers are only 1-2 weeks old, you don’t have enough and risk shortages. In either case it’s time to adjust your inventories.