Is it time to change your cleanroom suit?
Since 2003, IEST Operating Procedure Recommendation #IEST-RP0CC003.3 has recommended cleanroom fabrics, garment design, garment cleaning, and testing of cleanroom work clothes. The integrity and durability of cleanroom fabrics and the design of cleanroom suits have improved significantly in the past decade. Cleaning and testing of cleanroom suits have been standardized.
Some cleanroom factories replace cleanroom suits based on appearance evaluation standards or the number of times they are washed. Most cleanroom cleaning companies certify that their work clothes can generally be washed 100 times. So, what standards should be used to judge the replacement time of cleanroom suits?
The percentage change based on the original test data can be used as an objective standard to judge the replacement of cleanroom suits. Applying this standard to IEST-RP-CC003.3, the recommended standards for cleanroom suit replacement are as follows:
i. No more than one-quarter of the 3-inch patch area. The material of the hot paste must be the same as the work clothes material. The anti-static line must be straight and the patch must be completely attached to the fabric.
ii. The length of the seam shall not exceed 3 inches and shall be consistent with the Efb-2 category in the ASTM/FED-STD-751A standard, and the anti-static thread seam edge shall be straight.
iii. The stain size shall not exceed the area of a credit card. Adhesive materials that are easy to disperse dust are not allowed.
iv. Buckles and snaps shall be intact. Cloth reinforcement shall be sewn around the snaps.
In order to meet the above standards, baseline data of ICP/MS ion extraction test, ESD, SEM/EDX, HELMKE roller and ASTMF-51 tests of the garments shall be obtained during the initial application process. In daily use, routine tests such as ICP/MS ion extraction test, ESD, SEM/EDX, HELMKE roller and ASTMF-51 shall be performed and trend charts shall be prepared.
In summary, most cleanroom suits can last longer in real-world applications after 100 effective cleanings as recommended by the IEST-RP-CC003.3 operating procedure and particle testing meets IEST-RP-CC003.3 and ASTMF-51 standards. A typical year has 17 process cycles. Therefore, if the employees wearing the cleanroom suits always adhere to the cleanroom regulations, the cleanroom suits should meet at least 6 years of typical cleanroom use. The repair of cleanroom suits must be responsible for the effectiveness and durability of the repair of the suits by the designated fabric or workwear manufacturer.
If the cleanroom suit meets the above standards in terms of containment/shedding of active and inactive particles, ionic contamination and ESD, and its appearance is well repaired according to the above guidelines, there is no risk of contamination of the cleanroom, products and processes within the cleanroom. Therefore, if any part of the above standards is not met, it is recommended to replace the cleanroom suit