Moisture Stabilizer for Imported Raw Materials & Hot-Humid Stored Feed

Q: Why is zeolite considered for moisture and mold problems in stored feed from imported grains and meals?

Natural clinoptilolite is a moisture-adsorbing material that adsorbs and desorbs water vapor through its porous framework, so it is considered a moisture stabilizer that buffers free moisture (water activity) between compound feed and raw materials to reduce localized condensation and caking. Its adsorption and humidity-buffering behavior was quantitatively reported by Serhiienko et al. (2023), and the general basis for feed supplementation is summarized in the reviews by Papaioannou et al. (2005) and Ural (2014). However, zeolite is not a fungicide but a material that supports the moisture environment, so it must be used alongside moisture and temperature control of incoming raw materials.

Q: Does it prevent mold growth? Does it have a sterilizing effect?

It has no direct sterilizing effect. Mold growth is governed by the water activity (aw) of the feed, and clinoptilolite plays a supporting role by adsorbing excess water vapor to buffer the rise in aw in localized high-humidity zones, making growth conditions less favorable. It cannot restore already-contaminated feed, so it is appropriate to use it together with moisture specifications and mycotoxin testing at the intake stage.

Q: Does it help with raw materials in which mycotoxins (aflatoxin) have already been detected?

Clinoptilolite has been studied as a binder that adsorbs polar mycotoxins such as aflatoxin B1. Katsoulos et al. (2006) reported its binding capacity when added to feed, and the literature offers an estimate that 1 g of clinoptilolite adsorbs about 200 μg of aflatoxin B1. However, as the review by Liu et al. (2022) points out, aluminosilicate-based materials are strong against aflatoxin but have limited effect against non-polar and other toxins such as DON and ZEN. Therefore, raw materials with detected toxins must be handled together with toxin-specific dedicated binders and precise testing.

Q: How are the dosage and particle size determined?

Under FDA GRAS, the feed addition rate for anti-caking use is 2% or less of the total blend (21 CFR 582.2729). For moisture stabilization and anti-caking purposes, a range of 0.5–2% is usually considered, and 100-mesh powder is used first so it disperses uniformly in mash feed and premixes. For bulk silo floors and pallet desiccant pad applications, 14×40 mesh granules are also used. Refer to the product selection guide by application.

Q: Is there certification documentation?

KMIZEOLITE holds numerous certifications including OMRI Listed (KMI-10365), FDA GRAS (21 CFR 582.2729), TSCA compliance, and EN-71-3 PASS, and has been approved for use in the EU swine and poultry industries. Please verify on the certifications page.

The Challenge of Imported Raw Materials and Hot-Humid Storage: Moisture Fluctuation, Caking, and Mold

A substantial portion of domestic compound-feed raw materials depends on imported grains and meals. During long ocean transport and port/silo storage, raw materials undergo temperature and humidity fluctuations (moisture migration), and condensation inside containers and bulk carriers locally raises the water activity (aw). Once aw begins to exceed 0.70, storage molds such as Aspergillus and Penicillium proliferate more easily, leading to mycotoxin production (aflatoxin, ochratoxin, etc.), nutrient loss, and rancidity.

On top of this, storage under hot and humid climatic conditions causes caking of mash feed and premixes and even clogging of automatic feeding lines. In other words, the key variable in this field is not simply additive efficacy, but moisture-equilibrium management tailored to the moisture specification at the time of raw-material intake, the temperature and humidity of the storage environment, and the feed form (mash or pellet). Because feed additives are subject to regulation, the addition rate and use limits must also be confirmed first.

Why Zeolite Is Considered as a Feed Moisture Stabilizer

Natural clinoptilolite is a hydrated aluminosilicate mineral with micropores of 4.0–7.0 Å and a large internal surface area. This porous structure exhibits reversible adsorption–desorption (moisture-adsorbing, humidity-buffering) behavior, adsorbing water vapor when the surrounding relative humidity is high and releasing some of it again when it is low. When dispersed within a feed blend, it temporarily captures excess free moisture to buffer the rise in aw in localized high-humidity zones and acts as an anti-caking agent that maintains powder flowability. Serhiienko et al. (2023) quantitatively analyzed the moisture-adsorption and humidity-regulation performance of natural zeolite and reported its potential for humidity buffering in indoor and enclosed environments (Serhiienko et al., Energy and Buildings, 2023).

It should be noted that zeolite is neither a fungicide nor a preservative. Because mold growth is governed by water activity, clinoptilolite's role is limited to an indirect, supporting action of adsorbing excess water vapor to make growth conditions less favorable. The general basis for feed supplementation itself is summarized in the reviews by Papaioannou et al. (2005) and Ural (2014); both report that clinoptilolite has been widely considered as an anti-caking and adsorption aid in swine, poultry, and ruminant feed (Papaioannou et al., Microporous and Mesoporous Materials, 2005; Ural, Scientific Papers: Series D, Animal Science, 2014).

On the mycotoxin side, clinoptilolite has been studied as an adsorption binder for polar toxins such as aflatoxin B1. Katsoulos et al. (2006) reported its binding capacity when added to feed (Katsoulos et al., Microporous and Mesoporous Materials, 2006), and related research offers an estimate that 1 g of clinoptilolite adsorbs about 200 μg of aflatoxin B1. However, as the review by Liu et al. (2022) emphasizes, aluminosilicate-based adsorbents are effective against aflatoxin but have limited binding capacity against non-polar and other toxins such as DON and ZEN, so raw materials in which toxins have been detected must be handled together with toxin-specific dedicated binders and precise testing (Liu et al., Journal of Animal Science and Biotechnology, 2022).

KMIZEOLITE's natural clinoptilolite is 97% pure, mined and processed at the Amargosa Valley mine in Nevada, USA, and with a specific surface area of 40.0 m²/g, a stable pH range of 3.0–10.0, and thermal stability up to 700°C (handling pelleting-process temperatures), it is suitable for feed-blending processes. The FDA recognizes it as GRAS for use as an anti-caking agent in animal feed under 21 CFR 582.2729, and the European Union has approved its use in the swine and poultry industries.

KMIZEOLITE Key Properties

Item	Value
Clinoptilolite purity	97%
Cation exchange capacity (CEC)	1.6–2.0 meq/g
Specific surface area	40.0 m²/g
Pore diameter	4.0–7.0 Å
Stable pH range	3.0–10.0
Hardness	4.0–5.0 Mohs
Thermal stability	700°C
Specific gravity	1.89
Bulk density	45–54 lbs/ft³
Certifications	OMRI KMI-10365, FDA GRAS, TSCA, EN-71-3

Feed Moisture-Stabilization Application Examples: Review Scenarios by Storage Stage

Below are representative application scenarios in which zeolite is considered for imported raw materials and hot-humid storage environments. All feed additions are considered for anti-caking and moisture-buffering support purposes within 2% or less of the total blend per FDA GRAS criteria.

Addition to imported grain/meal blends: blending 100-mesh powder at 0.5–2% into mash compound feed that uses imported raw materials such as corn and soybean meal to buffer localized condensation and caking
Maintaining premix flowability: adding an anti-caking agent that reduces hygroscopic caking of vitamin and mineral premixes to ensure uniform metering and conveying
Bulk silo and pallet moisture-adsorption support: placing 14×40 mesh granules in silo bottoms and storage-pallet desiccant pads to mitigate excess moisture in the storage space
Distributing the load of toxin-risk raw materials: blending in clinoptilolite as an aflatoxin-adsorption aid when using mycotoxin-risk raw materials, while combining it with toxin-specific testing and dedicated binders
Pilot storage trial: dividing raw material from the same lot into a treatment group and a control group, storing for a set period, then comparing moisture, mold count, and toxin concentration before deciding on full adoption

Recommended Particle Size and Product Specifications

In the feed moisture-stabilization field, Powder (100 mesh) is suitable for mixing into compound feed and premixes, and Medium Granule (14×40 mesh) is suitable for silo and pallet moisture-adsorption placement. Since smaller particles are advantageous for uniform dispersion in mash feed, the powder form should be considered first for feed mixing. Refer to the table below to select the product group that fits your application.

Product group	Mesh	Particle size	Typical use
Powder	100 mesh or finer	<150μm	Pozzolan, feed, powder adsorption
Fine Granule	30×50 mesh	0.3–0.6mm	Water treatment, filtration, soil
Medium Granule	14×40 mesh	0.4–1.4mm	Filter media, bedding, flooring
Coarse Granule	8×14 mesh	1.4–2.4mm	Swimming pools, de-icing, large-scale filtration
Extra Coarse	4×8 mesh	2.4–4.8mm	Packed beds, air scrubbers

→ View products by mesh size · Product selection guide by application

Storage Trials and Field Review Points

When applying zeolite to imported raw materials and hot-humid stored feed, the following items must be checked together.

Dosage limit: Under FDA GRAS (21 CFR 582.2729), the feed addition rate for anti-caking use is 2% or less of the total blend. No pharmacological or preservative effect exceeding this limit is claimed
Intake moisture specification: Measure the moisture content and water activity (aw) of raw materials at intake, with the premise that zeolite is not intended to restore already-contaminated or high-moisture raw materials
Mold and toxin testing: Test mold count and toxin concentrations such as aflatoxin and ochratoxin by lot, and make clear that adsorption support is a complement to—not a replacement for—testing and management
Distinguishing toxin types: Clinoptilolite is effective against polar toxins such as aflatoxin but limited against DON and ZEN (see Liu et al., 2022), so use a dedicated binder together according to the toxin profile
Storage environment management: Inspect the temperature, humidity, ventilation, and condensation points of silos and warehouses, and evaluate additive effects together with environmental improvement
Certification confirmation: To use it as an organic-livestock feed raw material, confirm OMRI Listed (KMI-10365) compliance. The EU has approved use in the swine and poultry industries

→ View TDS (Technical Data Sheet) · View MSDS (Material Safety Data Sheet)

Feed Moisture Stabilization FAQ

Why is zeolite considered for moisture and mold problems in stored feed from imported grains and meals?

Natural clinoptilolite is a moisture-adsorbing material that adsorbs and desorbs water vapor through its porous framework, so it is considered a moisture stabilizer that buffers free moisture (water activity) between compound feed and raw materials to reduce localized condensation and caking. Its adsorption and humidity-buffering behavior was quantitatively reported by Serhiienko et al. (2023), and the general basis for feed supplementation is summarized in the reviews by Papaioannou et al. (2005) and Ural (2014). However, zeolite is not a fungicide but a material that supports the moisture environment, so it must be used alongside moisture and temperature control of incoming raw materials.

Does it prevent mold growth? Does it have a sterilizing effect?

It has no direct sterilizing effect. Mold growth is governed by the water activity (aw) of the feed, and clinoptilolite plays a supporting role by adsorbing excess water vapor to buffer the rise in aw in localized high-humidity zones, making growth conditions less favorable. It cannot restore already-contaminated feed, so it is appropriate to use it together with moisture specifications and mycotoxin testing at the intake stage.

Does it help with raw materials in which mycotoxins (aflatoxin) have already been detected?

Clinoptilolite has been studied as a binder that adsorbs polar mycotoxins such as aflatoxin B1. Katsoulos et al. (2006) reported its binding capacity when added to feed, and the literature offers an estimate that 1 g of clinoptilolite adsorbs about 200 μg of aflatoxin B1. However, as the review by Liu et al. (2022) points out, aluminosilicate-based materials are strong against aflatoxin but have limited effect against non-polar and other toxins such as DON and ZEN. Therefore, raw materials with detected toxins must be handled together with toxin-specific dedicated binders and precise testing.

How are the dosage and particle size determined?

Under FDA GRAS, the feed addition rate for anti-caking use is 2% or less of the total blend (21 CFR 582.2729). For moisture stabilization and anti-caking purposes, a range of 0.5–2% is usually considered, and 100-mesh powder is used first so it disperses uniformly in mash feed and premixes. For bulk silo floors and pallet desiccant pad applications, 14×40 mesh granules are also used. Refer to the product selection guide by application.

Is there certification documentation?

KMIZEOLITE holds numerous certifications including OMRI Listed (KMI-10365), FDA GRAS (21 CFR 582.2729), TSCA compliance, and EN-71-3 PASS, and has been approved for use in the EU swine and poultry industries. Please verify on the certifications page.

Inquiries and Sample Requests

If you are considering applying zeolite in the field of moisture stabilization for imported raw materials and hot-humid stored feed, please contact us through the channels below.

Notice

Whether the application is suitable may vary depending on field conditions, regulations, and test results. Before actual application, testing and review tailored to the field conditions must always be carried out first. Zeolite should be understood not as a universal solution for this field, but as a material that supports existing processes.