Sump trays are among the most important items of equipment for the safe storage of hazardous substances. Occupational health and safety and environmental protection rightly occupy a very central position in the company and have the highest priority. Hazardous substances and liquids used must always be properly assessed for their potential hazard and then stored accordingly. Prohibitions on combined storage in accordance with TRGS 510 or the VCI must be taken into account and complied with. Plants and operations in which substances hazardous to water are handled must be equipped and operated in such a way that contamination of the environment and hazards to employees and plants can be ruled out.
Sump trays as a suitable solution for the safe storage of hazardous substances
Single-walled hazardous goods containers or packaging such as small containers, canisters, drums or IBCs (Intermediate Bulk Containers) or KTCs (Cubic Tank Containers) are placed and stored in a particularly safe manner on drip pans with grids. An uncontrolled leakage of water-polluting liquids from the hazardous goods container is specifically prevented, as the tray catches the liquid and thus prevents contamination of the soil and the environment. The material used, the size and the retention volume can vary from model to model.
Choosing the right material for drip pans
When purchasing or for future use, the question arises as to what material the drip tray should be made of. The right choice of material is relevant to safety and should therefore be treated with appropriate care. It is crucial that the sump remains dimensionally stable and resilient even if it is filled with leaking liquids in the event of an accident (e.g. due to a leak caused by a forklift truck) and must be able to withstand not only the static pressure of the containers but also the hydrostatic pressure of the leaked liquid. In addition, a drip pan must be resistant to the spilled medium. A collecting tray made of normal steel cannot guarantee this, for example, in the case of aggressive acids or alkalis. For this type of storage, a tray made of stainless steel, polyethylene (PE), high-density polyethylene (PE-HD) or glass-fibre reinforced plastic (GRP) is recommended.
Flammable liquids may only be stored on sumps made of non-combustible material, as these, in contrast to sumps made of plastic, remain dimensionally stable and thus stable for longer in the event of a fire and thus at rising temperatures. For this reason, it is mandatory that only non-combustible materials such as steel or stainless steel are used for the storage of flammable liquids.
For a first rough overview regarding the resistance of the sump materials the following can be said:
- PE sumps for aggressive, water-polluting liquids, flash point >100°C
- PEHD drip pans for aggressive, water-polluting substances in high concentrations and a flash point >100°C
- GRP collection trays for aggressive, water-polluting substances, flash point >55°C
- Steel collecting trays for flammable, water-polluting liquids, flash point no restriction
- Stainless steel collecting trays for aggressive, flammable, water-polluting media, high chemical resistance, flash point no restriction
When selecting the correct sump materials, the resistance of the sump to chemicals and the grating must always be checked against the relevant resistance list. The resistance list for steel and stainless steel is DIN EN 12285-1: 2018 Table B.2 (formerly DIN 6601) and for plastics for example PE (polyethylene) and GRP (glass fibre reinforced plastic) the media list 40 from the German Institute for Building Technology in Berlin (DIBt) is considered the leading list. If the substance or mixture of substances does not appear in the said resistance lists, the resistance can be derived from the material of which the container is made, for example the drums in which the liquids are contained.
Selecting the right size drip tray
For the correct storage of hazardous goods containers or packaging, it is of course necessary that the base area is large enough so that the stored containers do not protrude over the edge of the tray. This is the only way to ensure that leaking liquids actually run into the collection tray and can be safely retained there.
In addition, the Water Resources Act (WHG) stipulates that the contents of the largest container stored above the sump must be collected. If the largest container is a 60 litre drum, the collection volume must therefore be at least 60 litres. If the largest container is, for example, a 200 litre drum, the collection tray must have a volume of at least 200 litres. If the largest container is a 1000 litre IBC / KTC, a collection tray with a retention volume of at least 1000 litres is required, and so on. In addition, the collection tray must be able to collect at least 10% of the storage quantity that is stored on or above the tray. I.e. concretely: if I store 12 pieces of 200l barrels in a rack, my largest container is 200l and my total storage volume is 2400l. The retention volume must therefore be at least 240l (maximum of largest container and 10% of total storage quantity).
Please keep in mind: If several containers are placed in one collection tray, they will displace space accordingly and thus possibly limit the required collection volume.
Attention! For water protection areas there are higher requirements for the retention volume. In most cases, a collection volume of 100% is required here. We will be pleased to advise you on this.
Verification of usability for collection trays
Usability certificates are required for collection trays and collection devices. For plastic collection trays made of PE, PEHD or GRP, ideal for acids or alkalis, the approval of the German Institute for Construction Technology (DIBt) is valid as proof of usability.
Steel sumps that comply with the steel sump guideline (StawaR - sumps with a collection volume of up to 1,000 litres) are considered a regulated construction product and as such are part of the DIBt building regulations list. Steel sump trays are therefore marked by the manufacturer with an Ü mark (declaration of conformity), which then serves as proof of usability. Steel sumps that do not comply with the StawaR require DIBt approval as proof of usability.
Manufacturers of collection trays must be a specialist company according to WHG for the production and installation/assembly. The corresponding certificates, i.e. specialist company certificate, DIBt approval, Ü mark and tray test certificate, are part of our documentation.
For drip pans that do not have a usability certificate, a suitability determination can be applied for at the water authorities of the district offices. For this purpose, an expert's report according to § 52 para. 1 no. 1 AwSV of an expert organisation must be submitted.
Collecting tray and filling station - the ideal combination
In addition to the classic, fixed sump tray made of steel with or without a grating, there are also various mobile models of sump trays with castors which make the internal transport of hazardous substance containers such as small containers or drums completely uncomplicated. These are high-quality sump trays made of PE or steel, which are equipped with a push handle and rollers. In most cases, such a sump tray can also be used as a mobile filling station. When purchasing such a model, in addition to the above-mentioned criteria, attention should primarily be paid to easy handling, robust handles and large filling areas. This is the only way to ensure safe decanting or filling of the respective liquids.
You can find further important information HERE on our info page on the subject of collecting trays.