Digital level measurement, automated inventory reports, and seamless monitoring of mobile liquid containers promise the chemical industry greater transparency, reduced safety stock levels, and more efficient supply chains. However, as soon as IoT sensors are to be used on IBCs, tanks, or other containers in potentially explosive atmospheres, a technically sound sensor alone is not enough.

This raises a crucial question for procurement:
Is the proposed IoT solution actually suitable for the intended application and properly ATEX-certified?

An incorrect choice can have far-reaching consequences: from delays in commissioning to additional testing and retrofitting costs, all the way to safety risks and compliance violations. At the same time, the topic is complex because procurement, occupational safety, production, maintenance, IT, and logistics all place different demands on the solution.

This article explains the key terms, typical use cases, and five points that chemical industry buyers should consider when procuring ATEX-compliant IoT sensors.

What Does ATEX Mean?

The term ATEX is derived from the French “ATmosphères EXplosibles.” It refers to European regulations for equipment and work areas where explosive atmospheres may occur.

There are essentially two directives to distinguish between:

• The ATEX Product Directive 2014/34/EU is aimed specifically at manufacturers and distributors of equipment and protective systems intended for use in potentially explosive atmospheres.
• The ATEX Operational Directive 1999/92/EC is aimed at operators or employers. Among other things, it addresses risk assessment, zone classification, and the safe use of appropriate work equipment. (Wikipedia)

For purchasing companies, this means that an ATEX-certified sensor does not relieve the operator of its own obligations. The device’s certification and the operational suitability test must be consistent with one another.

What is a potentially explosive atmosphere?

An explosive atmosphere can form when flammable gases, vapors, mists, or dusts mix with air in a specific ratio. If an effective ignition source is present, combustion can spread rapidly.

Even small electronic devices can contain potential ignition sources, for example through:

• electrical sparks,
• electrostatic discharges,
• hot surfaces,
• batteries or energy storage devices,
• defective electronic components.

For this reason, even a compact, battery-powered IoT sensor intended for use in hazardous areas must be appropriately designed, tested, and labeled.

Where are ATEX-certified IoT sensors used?

Typical applications in the chemical industry include:

Level monitoring of IBCs and tanks
Sensors continuously or at defined intervals measure the fill level of raw materials, auxiliary materials, or finished products.

Automated replenishment planning
Real-time inventory data can trigger ordering processes or alert suppliers early on to an impending stockout.

Monitoring of mobile containers
For mobile IBCs and reusable packaging, location, fill level, and movement data can be linked together.

Prevention of unplanned plant downtime
Consumption data helps ensure that critical materials are made available in a timely manner and prevents supply disruptions.

Inventory and Container Management
Companies gain transparency into which containers are located at which sites and how much product they contain.

However, the economic benefits are realized only if the sensor technology is suitable for actual use, both technically and from a regulatory standpoint.

1. The ATEX zone must be known before selecting sensors

One of the most common sources of error in the procurement process is selecting a sensor first and only then checking whether it is permitted for use in the intended environment.

The correct order is the reverse: First, the application area is evaluated; then, the appropriate device category is selected.

For gases, vapors, and mists, potentially explosive areas are typically classified into the following zones:

• Zone 0: An explosive atmosphere is present continuously, over long periods, or frequently.
• Zone 1: An explosive atmosphere may occur occasionally during normal operation.
• Zone 2: An explosive atmosphere does not normally occur during normal operation or exists only for a short time.

For combustible dusts, Zones 20, 21, and 22 apply accordingly.

The Pain Point for Purchasing

Purchasing professionals often receive a requirement such as “The sensor must be ATEX-compliant.” This statement is too vague. A device suitable for Zone 2 must not automatically be used in Zone 1 or Zone 0.

Therefore, before issuing a request for proposals, at least the following information should be available:

• intended installation location,
• existing ATEX zone,
• gas, vapor, or dust atmosphere,
• relevant substance group,
• required temperature class,
• Environmental conditions,
• Type and duration of use.

The zone classification should be specified in the operational risk assessment or the explosion protection document. It must not be assumed solely by the sensor supplier or determined on a blanket basis.

Relevant Target Groups

Purchasing: requires a clear, comparable specification for the request for proposals.

HSE and Occupational Safety: must ensure that the zone classification and device suitability match.

Production and site managers: are familiar with the actual process conditions and possible deviations from normal operation.

Maintenance: must know where and under what conditions the sensor is installed, tested, or replaced.

2. “ATEX-certified” is meaningless without complete labeling

ATEX is not a simple yes-or-no characteristic. What matters is not merely whether a supplier uses the term “ATEX,” but for which equipment group, category, atmosphere, and protection class the product is approved.

A typical Ex marking may include information on the following points, among others:

• Equipment group,
• device category,
• Gas or dust atmosphere,
• Type of protection,
• Explosion group,
• Temperature class,
• Equipment protection level,
• special operating conditions.

An example such as “II 2G” simply describes a Group II device for non-mining applications that is intended for gas-explosion-hazardous areas of a specific protection category. However, the complete marking contains additional information that may be relevant for operational approval.

The Pain Point for HSE and Engineering

Incomplete product data sheets often lead to lengthy coordination loops. Purchasing sees an ATEX logo, while HSE or electrical engineering later discover that important information is missing or does not match the application site.

Therefore, before placing an order, request at least the following documents:

• complete ATEX marking,
• EU Declaration of Conformity,
• ATEX certificate or type examination certificate, if required for the category,
• Operating and safety instructions,
• Information on special operating conditions,
• Information on approved batteries, accessories, and installation methods.

Pay special attention to an “X” at the end of a certificate number. It typically indicates that special conditions for safe use must be observed. These may relate, for example, to installation, the temperature range, protection against electrostatic charge, or battery replacement.

Practical Tip for Purchasing

Include the complete Ex marking as a required field in your supplier selection criteria. Instead of simply asking “ATEX available: yes/no,” the supplier should document the specific marking and the intended area of use.

3. It’s Not Just the Sensor—the Entire Application Scenario Matters

Certification always refers to a specific model and a defined intended use. Changes to installation, power supply, housing, or accessories can affect safe use.

For IoT sensors on IBCs and tanks, the following questions—among others—should be answered:

• How is the sensor mounted on the container?
• Is the sensor located in the hazardous area permanently or only intermittently?
• Is the sensor in contact with the medium?
• Is it permissible to open the device during operation?
• How is the battery replaced?
• Which accessories are approved?
• Can the housing become electrostatically charged?
• What are the ambient and surface temperatures?
• Is the sensor used on a moving container?
• Can the container move between different ATEX zones?

The Pain Point of Maintenance

An IoT project is often planned based on ideal operating conditions. In practice, however, the device must be installed, cleaned, maintained, and possibly repaired.

A solution that requires a container to be removed from the hazardous area or a special authorization to be obtained for every battery change can result in high operating costs. The same applies if sensors may only be installed by trained specialized personnel.

Purchasing should therefore evaluate not only the purchase price but the entire lifecycle:

• installation costs,
• required training,
• maintenance intervals,
• battery life,
• replacement procedures,
• Ease of cleaning,
• spare parts supply,
• Documentation requirements.

The Pain Point in Logistics

Mobile IBCs pose an additional challenge. A container may be located in one zone at the filler’s facility, then transported, and end up in a differently classified area at the customer’s site.

For scalable container management, it must be clarified whether the sensor technology is suitable for all intended stations and usage scenarios. Otherwise, this will result in different hardware variants, manual special processes, or restrictions on the use of the container pool.

4. Connectivity and Cloud Features Are No Substitute for Explosion-Proof Certification

In IoT projects, the focus is often on data transmission, dashboards, interfaces, and artificial intelligence. For operation in potentially explosive atmospheres, however, the physical safety of the end device remains the primary consideration.

Whether a sensor uses cellular, NB-IoT, LTE-M, LoRaWAN, Bluetooth, or any other wireless technology does not, in and of itself, indicate its ATEX compliance.

The following characteristics also do not substitute for appropriate Ex certification:

• low battery voltage,
• low transmission power,
• sealed housing,
• high IP rating,
• CE marking,
• suitability for industrial use.

The IP rating describes, for example, the protection a housing provides against the ingress of foreign objects and water. It does not automatically confirm explosion protection.

The Pain Point for IT and Procurement

IT departments rightfully examine aspects such as information security, data sovereignty, interfaces, and network coverage. Procurement must reconcile these requirements with HSE and technical specifications.

A suitable IoT solution therefore requires several levels:

1. secure and certified hardware,
2. reliable data transmission,
3. appropriate device management,
4. secure data processing,
5. usable interfaces and applications.

An ATEX-compliant sensor without reliable network coverage provides no operational value. Conversely, a high-performance IoT platform with unsuitable hardware may not be permitted for use in the relevant area at all.

Both perspectives must be taken into account in the requirements specification.

5. The business case over the entire lifecycle is crucial

ATEX-certified hardware is more demanding than conventional electronics in terms of development, testing, and production. A simple comparison of sensor prices therefore falls short.

For procurement, the decisive factor is the measurable benefit that the overall solution delivers. Typical benefits include:

• reduction in manual inventory checks,
• lower safety stock levels,
• fewer express deliveries,
• avoidance of material shortages,
• better container utilization,
• shorter turnaround times for reusable packaging,
• fewer container losses,
• greater planning reliability,
• automated ordering and replenishment processes,
• a better data foundation for customers and suppliers.

Management’s Pain Point

Pilot projects often yield interesting data but cannot be scaled economically. Reasons for this include, for example:

• time-consuming individual installations,
• missing interfaces,
• battery life that’s too short,
• unclear responsibilities,
• non-standardized certificates,
• poor network coverage,
• extensive manual data maintenance,
• lack of integration with ERP or scheduling processes.

A viable business case should therefore not focus solely on the price per sensor. What matters is the total cost per monitored container or measurement point over the planned service life.

These include:

• hardware and installation,
• connectivity,
• platform and licensing costs,
• integration into existing systems,
• Maintenance and replacement,
• Training,
• internal process costs,
• Decommissioning and disposal.

On the other hand, there are quantifiable savings and avoided risks.

The Pain Point of Operational Procurement

Procurement must reconcile differing interests: HSE demands safety, IT requires secure interfaces, production needs reliable data, and management expects a quick return on investment.

A structured proof of concept should therefore not merely verify whether a sensor is technically capable of taking measurements. It should test the entire process:

• Is the measurement quality sufficient under real-world conditions?
• Does data transmission work at the actual site?
• Is the hardware compatible with the existing ATEX zone?
• How labor-intensive are installation and maintenance?
• Are alarms and inventory data processed correctly?
• Can operational decisions be automated?
• Can the solution be scaled to additional sites and tanks?

Checklist: Questions Chemical Industry Buyers Should Ask Suppliers

Before making a procurement decision, at least the following questions should be clarified:

Certification and Scope of Application

• What is the complete ATEX marking?
• For which zones is the device suitable?
• Does the certification apply to gas, dust, or both?
• Which temperature class and explosion group are covered?
• Are there any special conditions for safe use?
• Are the declaration of conformity and relevant certificates available?

Installation and Operation

• What installation methods are permitted?
• Can the sensor be used on mobile IBCs?
• What environmental conditions are permissible?
• How are cleaning, maintenance, and battery replacement performed?
• Which components may be replaced by the operator?
• What training is required?

IoT and Integration

• What transmission technology is used?
• How is network coverage checked at the site of operation?
• What data is collected, and how often?
• Are there APIs or standard interfaces?
• How are devices, users, and access rights managed?
• How can alerts and reorders be integrated into existing processes?

Cost-Effectiveness and Scalability

• What are the total costs over the service life?
• What is the battery life achieved during the actual measurement interval?
• How quickly can additional containers and locations be connected?
• What service and replacement processes does the provider offer?
• What key metrics are measured in the pilot project?

Conclusion: ATEX must be part of the procurement process—not just the final check

ATEX-certified IoT sensors lay the foundation for digitally monitoring inventory, consumption, and mobile containers—even in demanding areas of the chemical industry.

However, for successful procurement, it is not enough to simply look for an ATEX logo on the data sheet. The certification must be appropriate for the zone, the substance, the temperature class, the installation, and the entire operational application scenario.

Successful projects therefore bring all relevant stakeholders together early on:

• Purchasing defines commercial and contractual requirements.
• HSE evaluates zone classification and explosion protection.
• Production describes the actual use case.
• Maintenance reviews installation and the product lifecycle.
• IT evaluates connectivity, security, and integration.
• Logistics considers container movements and scalability.
• Management evaluates benefits, risks, and the business case.

This transforms an isolated sensor project into a secure, scalable, and economically viable IoT solution.

Monitor Chemical Inventories Safely and Digitally

Do you want to make the fill levels, consumption, and locations of your IBCs and tanks more transparent—even in demanding industrial environments?

Packwise helps companies digitally map mobile liquid containers using smart sensors and a central IoT platform. Together, we analyze your use case, operational conditions, and requirements for scalable integration.

Talk to our IoT experts and learn how your container and inventory processes can be made safe, transparent, and automated.

Note: This article is for general information purposes only and does not replace an individual risk assessment, ATEX suitability test, or explosion protection consulting.