RoHS Category 9: Monitoring and Control Equipment

Understanding Restriction of Hazardous Substances in Electronics

Table of Contents

What Is RoHS?

RoHS stands for Restriction of Hazardous Substances. The RoHS directive, issued in the European Union, restricts the use of several hazardous materials in electronic and electrical equipment (EEE). All EEE products sold in the EU must comply with RoHS.

The RoHS directive currently limits the use of ten hazardous substances within EEE in the European Union. 

The ten hazardous materials included in RoHS must be used in electronics only below specific thresholds. The allowable amount for each substance except cadmium is 1000 ppm. The allowable amount for cadmium is 100 ppm.

The materials include:

Which Products Does RoHS Restrict?

It is important that manufacturers determine whether their product fits the definition of EEE, because all EEE, including smaller components, is subject to RoHS compliance requirements. RoHS defines EEE as: “equipment which is dependent on electric currents or electromagnetic fields in order to work properly and equipment for the generation, transfer and measurement of such currents and fields” (Directive 2011/65/EU). 

RoHS breaks down restricted EEE into 11 categories. The current categories are the result of one original directive and two additions known as RoHS 2 and 3. Read more: The Difference Between RoHS 1, 2 and 3

The current categories are:

  • Category 1: Large household appliances (eg. refrigerators)
  • Category 2: Small household appliances (eg. hair dryers)
  • Category 3: Computing & communications equipment (eg. computers)
  • Category 4: Consumer electronics  (eg. televisions)
  • Category 5: Lighting (eg. lamps)
  • Category 6: Power tools (eg. electric drills)
  • Category 7: Toys, leisure and sports equipment (eg. electronic dolls)
  • Category 8: Medical devices and equipment, such as in-vitro diagnostic devices, known as IVDs
  • Category 9: Monitoring and control instruments, such as thermostats and smoke detectors
  • Category 10: Automatic dispensers (eg. vending machines)
  • Category 11: Any EEE not covered in the previous ten categories. This includes EEE products such as two-wheeled electric vehicles, e-cigarettes and vapes, and electrical cables of less than 250 volts.

Categories 8 and 9 were added by RoHS 2 (Directive 2011/65/EU), and Category 11 was added by RoHS 3 (Directive EU 2015/863). The other categories were included in the original RoHS directive. As of July 22, 2021 all EEE under every category must comply with RoHS.

What Is Included in Category 9?

Category 9 includes all EEE that falls under the definition of monitoring and control equipment. While some categories are limited to household devices, category 9 includes monitoring and control equipment designed for industrial or professional use as well.

Monitoring and control devices are intended to control settings remotely, with some automation. Often, a monitoring and control device will receive information (for example, from a sensor) and make adjustments accordingly. Monitoring devices may also work to alert people to a specific event, such as machinery malfunction or the release of carbon monoxide.

Monitoring and control devices may be used in individual households (for example, a household thermostat) or in professional settings (for example, to monitor or control operations in an industrial factory).

Monitoring and control equipment that falls within the scope of RoHS include, but are not limited to:

x ray machine - rohs category 9
X-ray machine, an example of EEE covered by RoHS Category 9
Source: Medical Equipment MSL
  • Smoke detectors
  • Thermostats (used in buildings or individual rooms)
  • Carbon monoxide detectors
  • Weighing equipment, excluding household scales
  • Light meter
  • pH and conductivity meters, excluding those used for educational purposes
  • Chromatograph
  • Equipment used to calibrate other products
  • Test instruments
  • Portable digital thermometers
  • Surveying instruments
  • Voltmeters and ammeters when they are not used as a component in another product
  • X-ray imager
  • Spectrum analyzers
  • Oscilloscopes
  • Network cable tester
  • Semiconductor parameter tester
  • Signal generator
  • Waveform monitor
  • Optical power meter
  • Roadside traffic warning beacons
  • Traffic lights
  • Veterinary products used for measurement, monitoring or control
  • Burglar alarm systems
  • Laboratory ovens that control temperature
  • Some types of CCTV monitoring equipment if they monitor only (included in category 3 if they display images)

This list is not exhaustive, and manufacturers must assess their EEE on a case by case basis to determine if it is within the scope of products regulated by RoHS.


RoHS includes some general exemptions that may apply to monitoring and control equipment.

Monitoring and Control Equipment that Falls under Other RoHS Exemption Categories

RoHS includes categories of EEE that are exempt from regulation. Monitoring and control equipment that falls under the following exempted categories is also exempt.

  • Equipment necessary for security, including arms, munitions and material intended for military purposes
  • Equipment designed to be sent into space
  • Large -scale stationary industrial tools
  • Large-scale fixed installations
  • Means of transport for people or goods
  • Non-road mobile machinery exclusively for professional use
  • Active implantable medical devices
  • Permanently installed photovoltaic panels to produce solar energy
  • Equipment designed for business-business research
  • Equipment that is designed to be installed in another type of equipment that is excluded under RoHS.

For example, x-ray machines for luggage that are used specifically for national security are exempt from RoHS regulation. Another example is traffic lights that meet the criteria of large-scale fixed installation.

It is important that manufacturers are certain that their non-compliant product is included under one of the exempt categories, as placing a non-exempt, non-RoHS compliant product on the market can result in penalties. 

Read more about RoHS exemptions: What is RoHS Compliant?

Restricted Substances in Monitoring and Control Equipment with No Safe Substitutions

RoHS also includes more focused exemptions for hazardous substances whose use is permitted only in specific applications, such as in specific types of devices. Manufacturers can apply for these exemptions when no safe alternative to the restricted substance can be found and the product cannot be made otherwise.

For example, mercury can be used above 1000ppm if it is being used in high frequency RF switches and relays (which route high frequency signals) in monitoring and control instruments (although mercury is still limited to 20mg of mercury per switch per day). This exemption exists because a safer alternative has not been found.

A full list of substances exempt from restrictions when used in monitoring and control equipment can be found in Annex IV of RoHS 2 (Directive 2011/65/EU).

The RoHS directive pushes companies to search for alternative substances and processes that are RoHS compliant, even while using the original, exempted material. If a viable alternative is not found, extension of the exemption is possible.

To encourage innovation, these specific exemptions are temporary and expire on a set date. Manufacturers must remain aware of exemption expiration dates so as not to continue use of a material or application that is no longer exempt.

Impact of RoHS Category 9

RoHS may have several impacts on monitoring and control equipment included in category 9.

Increased Price of Production

RoHS restrictions on category 9 products may increase prices for monitoring and control equipment, as manufacturers must take steps to ensure RoHS compliance. Manufacturers of this equipment must use less hazardous and often more expensive methods to produce RoHS-compliant products. Additionally, testing products and ensuring RoHS compliance may be costly.

Buyers of monitoring and control equipment may face increased prices as a result of increased production costs.

Increased Scientific & Technological Innovation

However, increased costs come hand in hand with increased innovation. RoHS pushes scientific and technological progress forward, as monitoring and control equipment and production processes are redesigned to exclude restricted substances.

Read more about the impact of RoHS: What is RoHS?

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