ISO 16750-5 Road Vehicles - Environmental Conditions and Testing of Electrical and Electronic Equipment - Part 5: Chemical Loads

The standard "ISO 16750-5 Road vehicles - Environmental conditions and testing of electrical and electronic equipment - Part 5: Chemical loads," developed by the International Organization for Standardization (ISO), specifies the requirements for vehicle electrical and electronic systems and components, including electric drive systems and components with maximum operating voltages according to voltage class B. This standard describes potential environmental stresses and includes recommended tests and requirements for specific mounting locations on or within the vehicle. This standard addresses chemical loads. However, this standard does not apply to the environmental requirements or testing of systems and components for motorcycles and mopeds.

Conditions and tests for continuous contact with chemical substances may be determined from other standards or by agreement between the customer and the supplier.

Components and related parts that may come into contact with specified chemicals must be resistant to those chemicals. Components and related parts must be tested with all substances with which they are likely to come into contact, excluding materials that can be documented as immune to the contaminant. A material is considered immune to the contaminant if, at the time and temperature specified in this clause, it exhibits no change in properties sufficient to affect material performance. Documented evidence of immunity must be provided for all operating conditions likely to apply to the equipment tested, including operating temperature and self-heating effects, as agreed upon between the customer and supplier. The customer and supplier must agree on the type of chemical and the manufacturer. Resistance to specified chemicals should be considered as early as possible in the material selection process.

The purpose of the test is to determine whether systems or components are unacceptably affected by temporary exposure to contaminants. However, this test is not intended as a life test.

ISO 16750-5 is a critical standard that addresses the environmental conditions and testing of electrical and electronic systems in road vehicles. This standard focuses specifically on the chemical stresses that can affect these systems.

ISO 16750-5 applies to electrical and electronic systems and components in vehicles, including electric drive systems with maximum operating voltages classified as Class B voltage. This standard defines the potential chemical stresses that these components may encounter depending on their mounting location in or on the vehicle. It includes tests and requirements to ensure durability and reliability under these conditions. However, it is not intended for systems in constant contact with chemicals (e.g., fuel pumps immersed in fuel) or for motorcycles and scooters. Constant chemical exposure conditions are typically specified by other standards or through agreements between customers and suppliers.

The ISO 16750-5 standard addresses a number of chemical substances that can affect automotive electronics. For example,

• Fuels: Gasoline, diesel, and other fuels that can splash or leak into components, damaging plastic housings or seals.
• Oils: Engine, transmission and hydraulic oils that can compromise the integrity of connectors, seals and housings.
• Other substances: Cleaning fluids, road salts, and other environmental chemicals that components may encounter during vehicle operation.

This standard specifies tests to simulate exposure to these substances and evaluate the durability of materials and components. These tests ensure that electrical and electronic systems can withstand chemical stresses without compromising performance or safety. For example, tests can evaluate the effects of short-term exposure to fuels or long-term contact with oils by focusing on the component's specific mounting location (e.g., engine compartment, exterior, or interior).

ISO 16750-5 does not cover electromagnetic compatibility (EMC), which is addressed in other standards. Equipment parts, assemblies, or vehicle wiring harnesses and connectors are also excluded. However, some tests may still apply to these components. The standard emphasizes that it is not designed for components in constant contact with chemicals; such situations require specific standards or special agreements.

The automotive industry relies on the ISO 16750-5 standard to ensure the robustness of electrical and electronic systems in harsh chemical environments. Manufacturers use this standard to design and test components, ensuring they meet the reliability and safety requirements for specific vehicle installations. Advanced laboratories implement ISO 16750-5 to perform chemical load testing, helping manufacturers validate their components against industry standards.

The ISO 16750-5 standard plays a vital role in improving the durability of automotive electronics, which are increasingly critical in modern vehicles featuring advanced driver assistance systems, electric drives, and connected technologies. By stipulating rigorous chemical load testing, this standard helps prevent failures due to environmental stresses, increasing vehicle safety and longevity.

Essentially, ISO 16750-5 defines standardized procedures for assessing the resistance of components to chemicals such as fuels, oils, cleaning fluids, and road salts. The test methods are designed to mimic real-world exposure scenarios and ensure that components maintain their functionality and integrity. This standard categorizes tests according to expected exposure conditions, which vary depending on the type of chemical and the component's location (e.g., engine compartment, exterior, or interior). The key methods described in this standard are:

• Resistance to Fuels: The purpose of this test is to evaluate the effects of fuel exposure (e.g., gasoline, diesel) on components, particularly those in the engine compartment or near fuel systems. Components are exposed to the fuel by methods such as immersion, spraying, or brushing, depending on the expected exposure. The exposure time and temperature are determined to mimic real-world conditions (e.g., brief splash or prolonged contact). After exposure, components are examined for signs of deterioration, such as material swelling, cracking, or loss of functionality.
• Oil Resistance: The purpose of this test is to evaluate the durability of components exposed to oils such as engine oil, transmission fluid, or hydraulic fluids. Components are typically exposed to oil by immersion or application at high temperatures to simulate operating conditions. The tests evaluate the effects of prolonged or short-term contact, focusing on material properties such as seals, gaskets, or plastic housings. After exposure, components undergo visual and functional inspections to identify issues such as softening or brittleness.
• Resistance to cleaning fluids: The purpose of this test is to ensure that components can withstand exposure to cleaning agents, such as those used in vehicle maintenance or car washes. Components are exposed to cleaning fluids (e.g., detergents, windshield washer fluid) by spraying or wiping. The test simulates typical cleaning scenarios with defined exposure times and concentrations. Components are evaluated for surface deterioration, discoloration, or functional degradation.
• Resistance to Other Chemicals: The purpose of this test is to test the resistance of components to various chemicals, such as road salts, antifreeze, or battery acid, that may be encountered in specific environments. Components are exposed to the chemical by methods such as spraying, immersion, or cyclic exposure (e.g., wet/dry cycles for road salt). Tests may include accelerated aging to simulate long-term exposure. Post-test evaluations check for corrosion, material degradation, or electrical failures.

As a result, ISO 16750-5 is a fundamental standard for ensuring the reliability of electrical and electronic systems in ground vehicles under chemical stress. By defining specific tests and requirements, it helps manufacturers design robust components that withstand the harsh environments encountered in automotive applications. As the industry continues to innovate, ISO 16750-5 will remain a fundamental element for quality and safety in automotive electronics.

Our organization, which has been operating for many years and meticulously follows global developments in science and technology, employs a team of experienced professionals and a broad infrastructure to conduct testing, measurement, and analysis in a wide range of areas for businesses across all sectors. In this context, we also provide testing services in accordance with the ISO 16750-5 Road vehicles - Environmental conditions and testing of electrical and electronic equipment - Part 5: Chemical loads standard.