This question is often asked because many people simply have no idea that a shipping container can contain toxic substances. Millions of shipping containers arrive in Europe every year. Of these, around 33% contain an excessive concentration of hazardous gases. Harmful gases can enter containers in various ways.

Product fumes

  • For containers that are not fumigated but contain harmful substances, these may originate from the products (e.g. shoes, polystone items, etc).


  • Furthermore, harmful gases and/or vapours can also enter the container as a result of cargo leakage. A good example is “leaking” lighters and batteries, which can create an explosive atmosphere in the container.


  • First, these may have been added to the container in the country of origin. Examples include substances such as ethylene oxide, methyl bromide and hydrogen phosphide. These substances are used as fumigants and/or sterilizers (active fumigation).

Packing material

  • It is also possible for gases to come from the packaging material. These include Styrofoam, plywood pallets and glue.

The main reason for taking measurements in shipping containers is the safety of workers who must enter the container. There have been several serious incidents involving gases in containers in recent years. As a result, monitoring of this has been tightened considerably and containers are now treated as high-risk areas. The control of having sea containers measured is carried out by the labour authority. The labour authority is a government agency that checks whether employers and employees comply with the various laws, decrees and regulations on working conditions.

Such a measurement is already required during a physical inspection by Customs. The customs officer will only enter a container if it has been measured and found to be safe by a secondary gas measurer with a valid certificate.

In principle, what applies to Customs also applies to us. According to Article 3.5G of the Working Conditions Decree, every employer is obliged to have their employees work in a safe area. Through measurements and an RI&E, this safety can be guaranteed. Dealing with gases in import containers, the labour authority, has published an article about this (Dutch):

See what each substance is and does, and what complaints you can get if you inhale the substance. Read more: TOXIC GASES IN CONTAINERS

A gas measurement can be performed in several ways. In fact, there are numerous techniques that can analyse the presence of different gases in the air. During a measurement, explosive, oxygen and toxic substances must be measured at all times. A combination of sensors and an FTIR (Fourier Transform Infrared) analyser is used to obtain reliable measurement results. A measurement probe is inserted through the rubbers of the container. Attached to this probe is a hose that is connected to our equipment. The air in the container is then sucked in by the pumps of this equipment and an extensive analysis is carried out on the obtained measurement results by a gas expert who is specially certified for this purpose (MGK: medium gas measurer). This person will then indicate whether the container is safe to enter or not.