How to check if there is a peculiar smell in the air coming out of ULPA? Material outgassing and upstream pollution sources

The odor in the air coming out of the ULPA filter should be investigated from upstream pollutants, material release, cleaning residues and equipment operation. ULPA is used for particle filtration. Whether odor is controlled depends on the actual gaseous pollutants and treatment configuration. The problem of odor can easily go to two extremes: one is to directly replace the filter element, and the other is to increase the air volume to 'blow away'. Neither approach answers the question 'Where does the odor come from?' Odor is a signal of gaseous pollution, and the design goal of ULPA is particle filtration, which has limited ability to remove gaseous pollutants. The problem often lies on the upstream or material side. Aili Industrial's product line covers both particle filtration and gas filtration.Chemical filters target gaseous pollutants,Materials such as PTFE HEPA/ULPA filters can evaluate their gas release characteristics according to working conditions, and odor investigation can start from three directions: particle filtration, gas filtration and material compatibility at the same time.

1. Confirm the source and time: There are clues for new installation, heating, cleaning or specific processes.

Record whether it occurs during new installation, heating, cleaning or specific processes. Check the upstream air and adjacent materials to avoid directly judging a certain chemical composition based on the smell.

The time when an odor occurs is an important clue to locating the source. The odor that appears immediately after the installation of a new filter element may come from the outgassing of the filter material or sealing material; the odor that appears when heating up or restarting after shutdown may be related to the release of materials caused by temperature changes; the odor that appears after cleaning and disinfection may be related to detergent residue; the odor that appears when a specific process is running may come from process emissions. Aili Industry isHEPA/ULPA filters are delivered with a description of their material composition.The suitability of materials such as PTFE HEPA/ULPA filters can be confirmed according to working conditions during the selection stage, and the project party can narrow down the source range by comparing time nodes and material information. The relationship between levels and filtering requirements can be found inISO cleanliness level comparison。

2. Distinguish between particles and gas issues: Qualified filtration efficiency does not mean that odors have been removed

Qualified filtration efficiency does not mean that the gas has been removed; when gas control is required, the AMC solution for the target pollutants should be selected and the working conditions should be checked.

The detection index of ULPA is particle efficiency, and odor is gaseous molecules. The two are not in the same dimension. The ability of an efficient ULPA to remove gaseous pollutants depends on whether the filter material itself has adsorption or chemical removal functions. Conventional glass fiber filter materials mainly intercept particles and have limited effect on gas molecules. Aili Industry recommends confirming particle indicators and gas indicators separately during odor investigation.Chemical filters select media based on target pollutants,FFU chemical filters andBox-type chemical filters correspond to different installation scenarios, and particle filtration and gas filtration are configured separately. For the division of labor between particle and gas control, please refer toHEPA FAQs and Selection Guide。

3. Check the impact after treatment: Compatibility and release should be evaluated when replacing materials or cleaning agents.

Material or cleaning agent replacements should be evaluated for compatibility and release requirements. For process-sensitive items, testing needs to be agreed upon, and verification cannot be replaced by 'cannot smell'.

If the treatment of odor involves changing the sealing material, cleaning agent or filter media type, it is necessary to confirm the compatibility of the new material with the existing system and whether the new material itself releases at the operating temperature. Aili Industry isIn non-standard ULPA filter projects, the compatibility of sealing materials can be confirmed according to cleaning and disinfection methods.The sealing liquid type of the liquid tank seal ULPA filter is selected according to the use environment; after treatment, it is recommended to confirm the level of gaseous pollutants through testing instead of using the disappearance of odor as the basis for qualification. For methods of material compatibility and release assessment, please refer toULPA ultra-high efficiency filter FAQ and selection guide。

4. If new sealant smells after use, the material, curing and exposure conditions should be checked.

If there is an odor after using a new sealant, the material, curing and exposure conditions should be checked, and the fan should not be turned up to cover it up. The sealant may release volatile substances during the curing process. If the sealant is not cured sufficiently or a type of glue that is not suitable for a clean environment is used, the odor will persist.

Aili Industry isThere are requirements for the selection of sealing materials in the assembly of HEPA/ULPA filters and matching boxes. Sealing materials for clean environments have corresponding instructions on outgassing and curing conditions. When replacing sealants, the project party can confirm the curing time and exposure conditions according to the material instructions, instead of increasing the air volume to dilute the odor after it appears. For the selection of sealing materials at the equipment end, please refer toEFU FAQ and technical support。

5. Related questions and answers

Will switching to a higher grade ULPA eliminate the odor?
It cannot be inferred that gaseous pollution needs to be separately identified and configured to deal with it accordingly.

ULPA efficiency is qualified, why is there still an odor?
The detection index of ULPA is particle efficiency. Odors belong to gaseous pollution. Conventional filter materials have limited effect on gas molecules and need to be evaluated individually.

Does 'not smelling' mean the treatment is qualified?
uncertain. For items that are sensitive to the process, the level of gaseous pollutants should be confirmed through testing, and the disappearance of odor should not be used as the basis for judgment.

6. Related articles

ULPA ultra-high efficiency filter FAQ and selection guide

chemical filter

FFU chemical filter

HEPA FAQs and Selection Guide

7. Key points for selection and acceptance inspection

8. Product matching and technical support from Aili Industrial

Aili Industrial's product line covers both particle filtration and gas filtration.Chemical filters target gaseous pollutants,FFU chemical filters andBox-type chemical filters correspond to different installation scenarios;PTFE HEPA/ULPA filters and other materials can evaluate the gas release characteristics according to working conditions.HEPA/ULPA filter delivery is available with a description of the material composition.Non-standard ULPA filter projects confirm the compatibility of sealing materials according to cleaning and disinfection methods.The sealing liquid type of the liquid tank seal ULPA filter is selected according to the use environment; the assembly process has clean environment selection requirements and instructions for gas release and solidification conditions for the sealing material. Provide process objectives, installation drawings, operating conditions and acceptance requirements, and can further communicate ULPA standard specifications, non-standard interfaces, samples and batch matching. The specific parameters and test range are based on the confirmed model and technical documents.