Is that substance hazardous?

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Are there any dangerous substances present in a care unit of the hospital?

Yes, dangerous substances are substances and mixtures (solutions of substances) whose properties or the conditions under which they are used may hinder or endanger the health of workers or the environment. Some examples of dangerous substances that may be found in a care unit are cleaners (for example, bedpan washers), disinfectants, medicines (for example, cytostatics), inhaled anaesthetics, and gases.


May all dangerous substances be purchased without restriction?

No, not always. The purchase of the standard chemicals does not require a special permit, such as for radioactive substances. Certain groups require a permit for use or exemption, for example chemicals that can be used in the preparation of narcotics. The purchase of carcinogenic, mutagenic and toxic substances must be preceded by an assessment of the availability of a less dangerous alternative. If not, the reason why the purchase of the substance is necessary should be stated. For example, it is permitted to purchase (carcinogenic) cytostatics for treatment and research because these substances are indispensable in oncology. However, the use (and purchase) of some substances such as benzene as a solvent, cleaning agent or diluent is not permitted. There are good, less harmful alternatives available.

Are all chemicals dangerous substances?

No, not all substances have been classified as hazardous. This depends on the properties of the substance but also on the amount or concentration at which effects occur. If a substance (after evaluation in accordance with the European Directives) proves to be dangerous, the manufacturer or supplier must indicate this by such means as a hazard pictogram on the label.

The label must also contain the so-called H and P phrases. If a substance is not dangerous according to these Directives, this does not mean that it cannot cause any health effects. For example, sodium chloride (common salt) and water are not considered dangerous, but ingestion of large quantities of them can actually lead to health problems and even death. Paracelsus already said so: 'Only the dose makes the poison.'

Does each dangerous substance have a hazard pictogram?

No, not all of them. Dangerous substances are divided into 9 hazard classes. Most dangerous substances have a pictogram, but not all of them. There is always a signal word underneath the pictogram. Depending on the severity of the hazard in the hazard class, the signal word 'danger' or 'warning' is used.

You can see them below.

See also the section: Safety Information / Labelling Component: All GHS hazard pictograms.

Explosive substances (GHS01)

Substances and mixtures which may react exothermically in a solid, liquid, pasty or gelatinous state, even without the participation of oxygen in the air, can rapidly develop gases in this process and, under certain conditions, explode, ignite rapidly or explode if heated under partial confinement.


Flammable (GHS02)

Category 1 (signal word 'danger')
Substances and mixtures in a liquid state with a flashpoint <23°C and an initial boiling point < 35°C or; gaseous substances and mixtures which may ignite when exposed to air at normal temperatures and pressures.

Category 2 (signal word 'danger')
Substances and mixtures which may become hot and eventually ignite when exposed to air at a normal temperature without the supply of energy; or; solid substances and mixtures which may readily ignite after brief contact with a source of ignition and which continue to burn or smoulder after removal of the source of ignition, or;

  • liquid substances and mixtures with a flashpoint < 23°C and an initial boiling point > 35°C, or;
  • substances and mixtures which, in contact with water or damp air, develop a dangerous quantity of extremely flammable gases.

Category 3 (signal word 'warning’)
Liquid substances and mixtures with a flashpoint ≥ 23°C and ≤ 60°C. Due to the application of the CLP regulation, gas oil, diesel and light fuel oil with a flashpoint range between ≥ 55°C and ≤ 75°C can be classified as category 3.

Flammable substances of categories 1, 2 and 3 are marked with the same pictogram.

Oxidiser (GHS03)

Substances and mixtures which react violently exothermically in contact with other substances and/or mixtures, especially flammable substances. Extremely flammable.


Gases under pressure (GHS04)

This class includes compressed gases, liquefied gases, refrigerated liquefied gases and dissolved gases.

Corrosive (GHS05)

This class comprises all substances which are corrosive to metals and to the skin, as well as substances which may cause serious eye damage.


Acutely toxic (GHS06)

Substances and mixtures which, if inhaled, swallowed or absorbed via the skin, even in low quantities, cause death or acute or chronic damage to health.

Category 1 (signal word 'danger')
Substances and mixtures which are fatal if swallowed, in contact with the skin or if inhaled.

Category 2 (signal word 'danger')
The same as category 1 but less toxic, that is the effects occur as exposure to these substances is increased.

Category 3 (signal word 'danger')
Substances or mixtures which are toxic if swallowed.

Category 4 (signal word 'warning’)
Substances or mixtures that are harmful.

Acutely toxic substances of categories 1, 2, 3 and 4 are marked with the same pictogram.

Harmful, irritant (GHS07)

Non-corrosive substances and mixtures which may cause inflammation through direct, prolonged or repeated contact with the skin or mucous membranes. This class also includes sensitising and narcotic substances. These are substances which, inhaled and/or absorbed through the skin, are capable of eliciting such a reaction of hypersensitisation (hypersensitivity) that further exposure to the substance or preparation will cause characteristic adverse effects.

Long-term health hazard (GHS08)


Substances and mixtures which, inhaled, ingested through the mouth or absorbed through the skin, may cause hereditary genetic defects or increase the incidence of such defects.


Substances and mixtures which, inhaled, ingested through the mouth or absorbed through the skin, may cause cancer or increase its incidence.

Reprotoxic (toxic for reproduction)

Substances and mixtures which, inhaled, ingested through the mouth or absorbed through the skin, may cause non-hereditary defects in progeny and/or impairment of male or female reproductive functions or faculties, or increase the incidence of such defects or impairment

Hazardous to the environment (GHS09)

Substances which present or may present an immediate or delayed danger to one or more environmental compartments.


Does each substance have a hazard pictogram?

The following substances also have a hazard pictogram.


The radiation symbol is used for radioactive substances

Radiation symbol.


The biological risk symbol is used for biological agents and GMOs

Biological risk symbol.


In the case of cryogenic substances, the hazard symbol for 'low temperature' is used

Hazard symbol signifying 'low temperature'.


The hazard symbol for carcinogenic asbestos

Separate hazard symbol.


Is there a difference between mutagenic and carcinogenic?

Yes, mutagenic substances can cause damage to the hereditary material in the reproductive cells. Carcinogens may cause cancer on exposure. About half of the cytostatics are carcinogenic. No distinction is made between mutagenic and carcinogenic substances for the purpose of assessing the work situation and the measures to be taken.


Does each dangerous substance have H and P phrases on the packaging?

Yes, all dangerous substances in the 9 categories listed above have H (Hazard) phrases to indicate the hazard of the substance and P (Precautionary) phrases to indicate the safety measures. The phrases are used on the labels of the packaging and in the material safety data sheets. The H and P phrases, coded by number, are standardised descriptions of the potential health and safety hazards of the substance during normal handling and normal use.

With the advent of the Globally Harmonised System of Classification and Labelling of Chemicals (GHS), the orange square Environmental Management Act symbols will gradually be replaced by the diamond-shaped CLP pictograms.

CLP (Classification, Labelling and Packaging) is the abbreviation of the Dutch regulation that comes from the European EU-GHS legislation. The EU GHS is the European variant of the global GHS system initiated by the United Nations.

In Europe, EUH phrases also apply and constitute an extension of the global system. Not only are the symbols replaced by pictograms, the R and S phrases will also be replaced by the H (Hazard) and P (Precautionary) phrases.
Terms have also been changed in the CLP. The word preparation has been replaced by the word mixture.
See also the Safety Information/Labelling section, subsection: H phrases and P phrases for a complete overview of all the H and P phrases.

Is there a difference between a VIB and an MSDS?

No, MSDS is the English name for a material safety data sheet. MSDS stands for Material Safety Data Sheet. Nowadays the term SDS is also used.

The Dutch abbreviation VIB means VeiligheidsInformatieBlad (Safety Information Sheet). They are therefore different names for the same document.

See also the Safety Information/Labelling section, subsection: VIB or MSDS.

Do I always receive an MSDS if I order a dangerous substance?

No, suppliers are obliged to supply a material safety data sheet when a product is delivered for the first time. If a supplier makes interim changes to the MSDS, they are required to send the changed MSDS with the next order.

If you would like to have another MSDS at a later date, you can always request it from the supplier. Suppliers often have a website with safety information about their products. The UMCs have their own database with approximately 6,000 validated material safety data sheets and workplace instruction cards.

Is 70% alcohol a dangerous substance?

Yes, pure alcohol or ethanol is very flammable. It is assigned the pictogram for flammable liquids and warning phrase H225.

Alcohol 70% is a solution in water with a flashpoint of 21°C. The substance therefore falls into the flammable with warning phrase H225 category.

Ethanol has also been placed on the Dutch list of substances that are toxic for reproduction. This assessment is mainly based on exposure to alcohol due to (heavy) consumption.

In occupational situations, inhalation and skin absorption are more relevant. No concentrations are expected there at which these reprotoxic properties come into play. Under European OHS regulations, alcohol has therefore not been assigned a separate hazard pictogram or H phrase for reprotoxicity. Accordingly, European regulations do not require the reprotoxic property to be taken into account when disposing of ethanol as waste.

Does the label of a medicinal product indicate whether it is harmful or not?

No, most labels do not. The label of a medicinal product for the patient does not state whether it may have adverse effects on the health of workers. This could cause great confusion for patients. In case of doubt about the nature of the medicine, the Farmacotherapeutisch Kompas (Dutch online pharmacopoeia) or the patient information leaflet of the medicine can be consulted.

The medicine database ( contains the scientific product information of all medicinal products registered in the Netherlands. The pharmacist can also provide information about the medicine.

The UMCs have their own database with approximately 6000 material safety data sheets and workplace instruction cards for dangerous substances. The database also contains medicines. Most workers do not come into direct contact with medicines. For those who are likely to, it is important to realise that medicines are substances that sometimes work in very low doses (micrograms), so be careful!

Are inhaled anaesthetics dangerous substances?

Yes, being 'dangerous' for the worker obviously depends on the concentration of the inhaled anaesthetics and the duration of exposure. The inhaled anaesthetics currently used in hospitals are nitrous oxide, sevoflurane, isoflurane, desflurane and enflurane.

Nitrous oxide and halothane are classified as reprotoxic (toxic to reproduction) and are being used less and less and replaced with other substances.

Are all cytostatics carcinogenic?

No, but because of their effect, a large number of cytostatics are carcinogenic. They can also adversely affect reproduction and offspring by targeting not only malignant cells but also healthy cells. For practical reasons, no distinction is usually made between carcinogenic and non-carcinogenic. For specific information on cytostatics, please refer to the OHS Catalogue of Cytostatics on the website.

Are antibiotics harmful to workers?

Yes, possibly. Little is known about the harmful effects of medicines, including antibiotics and antiviral drugs, on the health of staff who are exposed to small amounts on an almost daily basis.

There are a few known cases of staff who developed an allergy or built up resistance to antibiotics. Given the impact of medicines (antibiotics) on patients and the somewhat persistent lack of data on the effects of low exposure, prudent work practices with the lowest possible risk of exposure are in order.

Is blood a dangerous substance?

Yes, blood is classified as a dangerous substance within the hospital: it is potentially contaminated with pathogenic micro-organisms. This also applies to other bodily fluids (amniotic fluid, liquor, ascites and pleural fluid). However, you do not need to mark this on a blood tube itself with the 'biological risk' hazard symbol, because in a hospital environment it is assumed that all blood products may be contaminated.

The hazard symbol is sometimes required when sending the blood samples and is always required when blood is disposed of as waste in a waste drum or needle container. Blood samples are then subject to the ADR transport rules with special requirements for packaging and labelling. Larger amounts of blood are disposed of in hospital waste drums with UN code 3291. Blood tubes for the laboratory are sent as diagnostic samples in special UN 3373 'BIOLOGICAL SUBSTANCE CATEGORY B’ packaging.

Is urine dangerous?

Yes, sometimes.
The excretion products (sweat, vomit, urine and faeces) of patients who have been treated with, for example, cytostatics or radiopharmaceuticals, are contaminated with them during the risk period and are then classified as 'dangerous substances’. It should be handled with caution to minimise the likelihood of exposure. Of course, you should always work carefully and hygienically with excreta.

Is a cleaner or disinfectant a dangerous substance?

Yes, in a concentrated form cleaners tend to be irritant or corrosive. They are often purchased in a concentrated form and then diluted before use. Most cleaners also contain more than 10% lye.

This should be stated on the label and in the MSDS. You can check in the manual or instructions for use whether the used concentration is still dangerous. Disinfectants also qualify as dangerous substances. This is the case if they contain a dangerous substance such as alcohol, glutaraldehyde, formaldehyde, phenol and chlorine and iodine compounds.

Is a diluted NaOH solution dangerous?

Yes, up to a certain concentration. The danger of the solution depends on the concentration. Concentrated caustic soda is corrosive. The packaging must display the 'corrosive' pictogram and the H phrase H314 'causes severe skin burns.

When diluted, the effect decreases. Below the concentration limit of 5% (1.3 M), this mixture is only irritant. This is shown with the exclamation mark pictogram with H315, H319). If you dilute the mixture to less than 1% (0.25 M), it is no longer dangerous and a pictogram and H phrase are no longer required at all.

A simple overview showing when diluted chemicals are still dangerous?

Yes, the calculation rules for when a solution is a dangerous substance are laid down in European Regulation (EC) No. 1272/2008. The concentration limits that determine when a waste product is still hazardous are set out in the European Waste List (EURAL).

The following simplified scheme, based on it from GHS, indicates that a solution is still a dangerous (waste) substance at a concentration (wt. %) of more than:

0.1% Acute toxicity category 1, 2, 3
Hazardous to the aquatic environment category 1
Carcinogenic, mutagenic

0.3% reprotoxic (or harmful through breast-feeding)

1% Acute toxicity category 4
Skin corrosion/irritation
Severe eye damage/eye irritation
Hazardous to the aquatic environment category 4
Suspected to be carcinogenic, mutagenic

3.0% suspected to be reprotoxic

As a rule of thumb, the following concentration limits can be used:
For a high-risk substance: 1%
For a very high-risk substance: 0.1%

Pdf overview

Must the label of a dangerous substance be provided in Dutch?

The label on the packaging is usually drawn up in the Dutch language. If the substance is intended for laboratory use and the contents do not exceed 1 litre, the supplier may also use the English, German or French language.

What is Specific Hospital Waste?

This is waste from human and animal health care, which requires particularly close attention for ethical, environmental, hygiene and safety reasons.

Some examples of specific hospital waste are:

  • waste from clinical and microbiological laboratories which is bacterially, virally or fungally contaminated;
  • sharp objects such as injection needles, cut-off capillaries, scalpels;
  • instruments and blood tubes;
  • blood, plasma and other pasty and liquid wastes (such as wound fluid, drain fluid and pus) that have not dried up (and are therefore present in liquid form);
  • cytostatics or residues of cytostatics.

Are the gloves in our hospital latex-free?

No, all UMCs have switched to low-latex and powder-free gloves. If there is no need to use latex, use nitrile or vinyl gloves. As a result, the development of any latex allergy is already reduced considerably. Most UMCs have already chosen non-sterile examination gloves made of nitrile.

Is there a reliable site with information about dangerous substances?

Yes, the UMCs have a database of dangerous substances containing thousands of substances.

The database can be accessed from your workstation on the intranet at every UMC without having to enter a login code or password.

In addition to material safety data sheets, the database also contains workplace instruction cards. These are validated documents in Dutch and English.

Ask your OHS service or take a look at the What does your UMC do section for extra information.