Why Use a Humidity Indicator Card?

Why Use a Humidity Indicator Card?
Published On:October 11, 2018 Revised On:December 27, 2023

Humidity is a common packaging problem with a wide range of moisture-sensitive products and materials during transpiration and storage. Heightened moisture levels can damage delicate electronics, pharmaceuticals, and even invaluable artefacts.

Humidity indicator cards (HICs) are a reliable packaging solution for monitoring and assessing humidity levels within the packaging. During the packaging of moisture-sensitive products, the moisture-indicating cards undergo visual changes corresponding to their surroundings’ relative humidity. As a result, they provide a quick and convenient means of gauging the moisture content within the packaging.

Importance of Monitoring Humidity

Moisture-sensitive products, such as electronics, pharmaceuticals and food items, are highly susceptible to moisture damage. High humidity levels can lead to corrosion, mould growth, degradation of product quality and shortened shelf life. By monitoring humidity within the packaging, potential moisture-related issues can be detected early, allowing corrective actions to be taken to maintain product integrity.

Many products have specific humidity requirements to maintain their freshness and extend their shelf life. Monitoring humidity levels within the packaging helps ensure the conditions suit the product. If humidity exceeds the recommended range, it can accelerate spoilage, bacterial growth, and chemical reactions that affect product quality and safety.

Packaged goods may be exposed to varying environmental conditions during transportation and storage, including temperature and humidity fluctuations. Monitoring humidity in packaging helps evaluate how well the packaging protects the product during these transitions. It enables logistics providers and retailers to identify any potential risks of moisture damage and take preventive measures, such as using moisture-resistant packaging or implementing humidity-controlled storage environments.

Proper packaging design, moisture barrier materials, and moisture control measures such as desiccants or humidity indicators can help mitigate these risks and maintain product quality throughout its lifecycle. Proactively safeguard products and prevent potential damage by monitoring humidity levels.

What is a humidity indicators card?

A humidity indicator card (HIC) is a small card or label that contains chemicals that change colour in response to the humidity levels in the surrounding environment. The card is typically made of paper or a porous substrate with indicator spots or patches impregnated with a moisture-sensitive chemical.

The moisture-sensitive chemical is usually a salt or a mixture of salts that can absorb or release moisture depending on the humidity. The most commonly used chemical is cobalt chloride, which changes colour from blue (dry) to pink (humid) as it absorbs moisture. However, due to health and safety concerns associated with cobalt chloride, alternative chemicals like cobalt-free humidity indicator cards are used.

Each card has several indicator spots or patches calibrated to change colour at a specific humidity level or range. The spots may have numerical or colour-coded markings indicating the corresponding humidity level. When exposed to humidity, the chemicals in the indicator spots react to the moisture in the air, causing a visible colour change. By comparing the colour of the indicator spots with the reference chart provided by the HIC, users can determine the approximate humidity level in the environment where the card was placed.

Moisture indicator cards are widely used in various industries to monitor and assess humidity levels, protect moisture-sensitive products, ensure proper packaging, and maintain optimal storage conditions. They offer a quick and visual indication of humidity and assist in making informed decisions regarding product quality and preservation.

Why use Humidity Indicator Cards

Many products are moisture-sensitive, especially in electronics, pharmaceuticals, and food industries. Excessive humidity can damage or degrade these products, leading to malfunctions, spoilage, or reduced effectiveness. Moisture-sensitive indicator cards help ensure the products remain within acceptable humidity limits during storage, transportation, or manufacturing.

HICs are often placed inside packaging materials, such as silica gel packets or moisture barrier bags, to verify if the packaging adequately protects the contents from humidity. Regularly monitoring the moisture control indicators makes it easier to identify any breaches in the packaging that may allow moisture to enter.

Humidity can affect the quality and shelf life of various products. The humidity tracking cards help determine whether the storage conditions are suitable for maintaining the desired quality and extending the shelf life. By monitoring humidity levels over time, manufacturers and suppliers can make informed decisions about the storage or shipment of their products.

Applications of HIC

Humidity indicator cards are widely used in various applications where monitoring and controlling humidity levels is critical. Some of the common applications of humidity indicator cards include:

  1. Electronic and Electrical Devices: Humidity indicator cards are used in electronic and electrical devices to ensure that the humidity levels are within acceptable limits. Excessive humidity can cause corrosion, oxidation, and damage to sensitive components, leading to malfunctions or failures. The cards help indicate whether the packaging or storage conditions suit these devices.
  2. Pharmaceuticals and Medical Supplies: Many pharmaceutical products and medical supplies are sensitive to moisture. Humidity indicator cards are used to monitor the humidity levels in packaging to ensure the quality and efficacy of the products. These cards are particularly useful for moisture-sensitive medications, diagnostic test kits, and medical devices.
  3. Food and Beverages: Humidity measurement cards are used to monitor and control moisture levels in packaging in the food and beverage industry. They help indicate if the packaging has been compromised, allowing moisture to enter, which can spoil the food or beverage products. The cards help maintain freshness, extend shelf life, and ensure product quality.
  4. Optics and Optoelectronics: Optical instruments, lenses, and optoelectronic components can be affected by high humidity, leading to fogging, condensation, or damage. Humidity indicator cards are used in these applications to indicate the presence of moisture and ensure proper storage and handling conditions.
  5. Aerospace and Defense: The aerospace and defence industries utilise humidity indicator cards to monitor the humidity levels in sensitive equipment, such as avionics, radar systems, missiles, and other electronic components. By using these cards, potential risks of moisture-related damage or malfunction can be mitigated.
  6. Automotive and Transportation: Moisture indicator cards are used in the automotive and transportation industries to monitor humidity levels while storing and shipping automotive components, spare parts, and sensitive equipment. They help ensure that the products are not exposed to excessive moisture, which can cause degradation or failure.
  7. Museums and Archives: In preserving artwork, historical artefacts, and documents, maintaining appropriate humidity levels is crucial. Humidity indicator cards monitor and control the humidity within museum showcases, storage facilities, and archives to prevent damage, mould growth, and deterioration.
  8. Consumer Goods: Various consumer goods, such as electronics, clothing, leather goods, and musical instruments, can be affected by moisture. Humidity monitoring cards are used in the packaging of these products to indicate if there has been any moisture intrusion during storage or transportation.


Monitoring humidity in packaging is essential for protecting moisture-sensitive products and materials during transportation and storage. Excessive moisture can cause damage, corrosion and reduce shelf life, while inadequate humidity can cause dryness and degradation.

Humidity indicator cards (HICs) offer a reliable solution for monitoring and assessing humidity levels within the packaging. They undergo visual changes corresponding to the surrounding humidity, providing a quick and visible indication of moisture content. Using HICs, companies can proactively detect and address potential moisture-related issues, ensuring product integrity, extending shelf life, and maintaining optimal storage conditions.

The applications of HICs span various industries, including electronics, pharmaceuticals, food, optics, aerospace, museums, and consumer goods, where moisture control is critical for product quality and preservation. By incorporating humidity monitoring solutions like HICs, businesses can mitigate risks, enhance customer satisfaction, and preserve the integrity of their products.