Storage of hazardous substances in the laboratory (GHS)

Based upon the labelling according the Globally Harmonized System (GHS).

For more information about the rules about labelling see: Labelling hazardous substances (WMS or GHS).

PGS 15 shows guidelines for the storage of packaged dangerous substances in the field of fire safety, occupational and environmental safety. The directive is used by the authorities in the provision of the Environmental Management Act permit

The PGS-15 is based on the transport legislation (European ADR).
The PGS-15 is particularly drawn for industrial warehouses and storage facilities. The packages here are the packages (and labels) used in the transport of dangerous substances.

The different classes in the PGS 15 are:

Through the presence of hazardous substances at the UT, risks may exist or arise. Hazardous substances are present at different places. Work stocks at or near the workplace, remnants or waste chemicals and storage of larger work stocks and products in warehouses

If the storage of hazardous substances does not comply with the rules, a chain of events can sometimes arise, due to one leaky packaging. This can lead to an emergency. Consider, for example, a corrosive substance, the packaging of which leaks and which seals the packaging of another substance. If that is a volatile and flammable liquid, there is a risk of fire and explosion. There may also be reactions between the two substances, which may lead to additional danger. For this reason, all sorts of requirements have been imposed on the storage of hazardous substances, for example the use of drip trays.

Laboratories at the UT are characterized by the presence of many different types of substances, often in limited volumes. The packaging size is up to 2.5 liters for liquid bottles to 20 liters for barrels. The packaging label according GHS is used. Many bottles are for direct use in the laboratory. There are also containers for solid and liquid hazardous waste.

The storage of hazardous substances must be in accordance with the UT’s environmental permit (in accordance with PGS 15 guidelines or equivalent). General starting points for storage of hazardous substances are:

• Toxic substances to be placed in a lockable (chemicals) cupboard;
• Irritating substances in (aired) safety cupboards;
• Acids and bases – separated – to be stored in drip-trays in aired cupboards;

- Flammable substances to be placed in aired fire-resistant cupboards (compliant with NEN-EN-14470-1). Flammable substances in the refrigerator only if it is explosion-proof and it concerns small quantities (< 100 ml) that have been properly closed off. It needs to be properly indicated on the refrigerator whether it has been made explosion-proof. If the refrigerator has not been made explosion-proof, it needs to be clearly stated on the refrigerator that it is unsuitable for storing combustible substances. See for more information: 

Further information on (aired) fire-resistance refrigerators can be obtained from the VGM-er.

- Oxidising substances only in small quantities to be placed with other substances (e.g. concentrated acids) or in separate cupboards;

Reacting substances that can release hazardous gases or vapors or create dangerous situations such as explosions or heat generation must be stored compartmentalised. Consult the chemical card book or safety data sheet of each substance regarding possible hazardous combinations of chemicals.

Joint storage in one compartment is prohibited for, among other things, the following combinations:

• Acids and alkalis;

• Acids and chlorite and hypochlorite solutions;

• Nitric acid in formic acid, acetic acid or formaldehyde solutions;

• Acids and cyanides;

• Acids and sulphides

These substances must be stored separately in drip trays in a designated container storage facility. When storing in a safety cupboard, a separation of materials from incompatible combinations must be ensured. This can be done by placing the different categories of substances in separate drip trays. A drip tray must be present for each category to be compartmentalised.
The table below indicates which classes must be stored together or separately. The table can be deviated from in a motivated way on the basis of e.g. safety data sheets or if substances can react but are present in such a limited concentration that no reactions are to be expected with special risks.

Explanation:
V: Storage of substances to be separated in separate compartments. If no separate compartments can be realized, storage must take place in a separate fire compartment, in other words a separate storage facility.

B: Separate storage unless it has been assessed that the substances do not react with each other or both substances are classified as solid. The assessment (B) is in principle based on
the information as stated in the Safety Data Sheets (MSDS), of for generic products the information as stated in the Chemistry Card Book.

-: Separate storage not necessary.

*: Substances with acute toxicity or CMR substances must be distinguished in a separate fire compartment, or the compartment where these substances are stored, in such a way that the employees become more aware of the dangers.
For the other toxic substances, it is desirable to use a separate compartment with substances of class 3

 A comprehensive overview of dangerous reactions for combinations of different substances is included in appendix 2 of the regulation hazardous waste UT.

In a laboratory, the work stock must be as small as possible, but it may preferably be not more than 1 kg or liter per m2 or equal to the stock required for the consumption of one day or one batch ". The calculation of 1 kg or liter per m2 is in line with the safety standards for fire safety. The working stock in a laboratory is the amount of hazardous substances that is strictly necessary for carrying out the analyzes and experiments, such as the reagents in the analyzers and the reagent bottles for determinations. The quantity must also be kept as low as possible from the working conditions legislation and measures must be taken to prevent exposure to undesirable events. Therefore, place the working stock of (flammable) liquids on the laboratory table as much as possible in a drip tray. Store the barrels and bottles at the end of the day in the appropriate safety cupboard. Work stocks are often too large and remain too long. Fume cupboards may not be used as storage space for work stocks. Waste kegs that are used for the collection of hazardous waste are not covered by a working stock: they are mainly aqueous solutions. Full waste drums should be disposed of as quickly as possible, if this is not possible, storage will take place in a safety cabinet. When hazardous waste is transported through the corridors and in the elevators, this must be transported on a cart in a drip tray.

Definition and requirements for a drip tray according to PGS 15
A drip tray is a liquid-tight facility with limited collection capacity, of which the soil protection effect is ensured by targeted supervision and efficient emptying. The drip tray must be designed in such a way that it can withstand the effects of liquids stored above it. Requirements are set for e.g. the collection capacity and the resistance to the stored substances. A drip tray must have a collection capacity of at least 110% of the contents of the largest packaging unit, or if this is greater, 10% of the contents of all stored substances. This collection capacity can not prevent calamities, but the risks are considered acceptable. Any liquids leaked must be removed from the drip tray.

Calculation example drip tray:
The following packages are available: 10 barrels with 5 liters, 10 bottles of 2.5 liters and 25 bottles of 1 liter, in total a storage of 100 liters.
110% of the contents of the largest packaging unit = 110% of 5 liters = 5.5 liters.
10% of the content of all stored substances = 10% of 100 liters = 10 liters. The collection capacity of the drip tray should therefore be at least 10 liters.

The drip tray must be able to withstand the effects of liquids that are stored. There are e.g. plastic and steel drip trays.

In the use and storage of hazardous substances in a laboratory the GHS classification is used and not the ADR classification..

The table below is for the different hazard classes, based on the hazardous label of a substance and the hazard statements, the method of storage in a laboratory displayed.

SUMMARY RULES STORAGE DANGEROUS SUBSTANCES

• Dangerous substances must be stored in suitable cupbaords for the relevant hazard category.
• Dangerous substances that can enter into dangerous reactions with each other must be stored separately from each other. Use suitable separate drip trays.
• A working stock of hazardous substances may only be stored outside the storage box for a working day
• Use suitable transport when transporting dangerous goods (or waste): cart with drip tray and / or carrier bucket
• Collection capacity drip tray at least 110% of the contents of the largest packaging or, if this is larger, 10% of the contents of all stored substances together.
• Drip tray must be able to withstand the effects of the liquids that are stored.