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Bulk fill dispensers are one of the most popular soap dispensing systems in commercial washrooms, and for good reason. The system is cost effective, you have flexibility in changing soap and soap suppliers, and the plastic soap container is recyclable. However, there is a serious risk where bulk fill soap becomes contaminated with bacteria which causes the soap to congeal and ultimately results in premature soap dispenser failure.

Congealing soap is a known issue in washrooms, and from experience onsite, we need to make you aware of the possible implications that arise without a robust maintenance regime.

This report was compiled from a previous case study when the multifeed system dispensers failed due to congealed soap and the implications that followed. We will address the catalyst conditions of why the soap dispensers failed and provide recommendations to prevent soap from congealing in multifeed bulk fill systems.

Dolphin Foam Soap Cartridge Multifeed System

Washroom project brief

Largely due to budget constraints, the client swayed towards the bulk fill dispensers for their washroom project. We offered our cartridge soap system as a more suitable and efficient solution due to the potential risks of multi-feed systems, but this option was out of their budget.

The Dolphin cartridge dispenser is a patented and unique product, and the cartridge soap is not replaceable by other suppliers. This factor deterred the client from choosing our cartridge soap system because they would not have flexibility in changing their soap supplier should they wish.

How did the soap become contaminated?

Although we cannot determine how the soap became contaminated in the dispensers, we know of catalyst conditions that increase the risk of opportunistic pathogens infiltrating soap systems.

Backed by scientific research, any combination of the below catalysts could have caused the soap to congeal and the soap dispensers to fail:

1. Foreign particles in the air

Bacteria is present on host particles in the air such as dirt, dust, fine fragments from paper towels or toilet tissue, particles blown out from hand dryers etc. The particles can make their way into the soap especially when a bulk fill tank is opened and refilled.

Nothing can be done to completely eliminate this natural pathogen from entering a multifeed system because bacteria is omnipresent – there is no escaping it.

2. Insufficient maintenance regime

The maintenance regime should be robust and consistent. The bulk fill dispensers, filters, gauzes, and pipework must be regularly drained out, cleaned, and sanitised before refilling the system. Without a strict maintenance schedule, the soap becomes contaminated with environmental bacteria and starts to solidify at a rapid rate. But at the same time, even with a robust cleaning schedule, bulk fill dispensers are still at a higher risk of contamination.

We have often discovered that facilities teams are more likely to top up a large bulk fill container before it reaches anywhere near empty, thus leaving a combination of old and fresh soap in the reservoir – the perfect concoction for bacteria to start growing.

The maintenance policy should stipulate a half fill top up, at the most, is required when the soap reservoir depletes, as this will allow fresh soap to continue moving through the system. Facilities teams must perform the topping up procedure carefully, hygienically and only when the bulk fill dispenser is empty to prevent contamination of the reservoir.

3. Long term vacancy due to covid-19 restrictions

The lockdown caused worldwide evacuation from public places into our homes. Due to the vacant building with no cleaning procedure before or during the extended closure, the soap was left stagnant in the system and ultimately encouraged the growth of bacteria.

If the soap is not moving through the dispensers, it can cause congealing and blockages with the rapid build up of bacteria.

4. Public washroom with high foot traffic

This particular case study is a public development where the washroom design accommodates high foot traffic and heavy usage of the facilities. The risk in these types of washrooms is the more often a soap dispenser is used, the more often it will need to be replenished, leaving the bulk fill dispenser vulnerable to bacteria exposure more frequently.

If the multifeed system was not regularly and efficiently cleaned during the refill intervals, then the improper maintenance would have been a catalyst in the contamination that caused the soap to congeal and damage the soap dispensers.

5. Type of soap used

Regardless of whether it is a foaming soap refill or a liquid soap refill, they both run the risk of bacterial contamination. Both foam soap and liquid soap can congeal and cause blockages in the multi-feed system. In this case study, the type of reservoir was a foaming soap refill.

6. Room temperature

Heat accelerates bacteria and fungi growth. If there is insufficient ventilation or temperature control in the washroom, the hostile ambience can turn into a condition that encourages bacteria growth which will replicate at an exponential rate.

Washrooms tend to be warm and humid. These conditions are ideal for bacteria growth, especially inside mirror cupboards and enclosed spaces near hot water pipes.

Failed bulk fill dispenser discharging runny liquid

What were the implications?

Within four years, our client notified us that our soap dispensers were not performing and they needed a solution to fix the problem urgently. We discovered all the bulk fill dispensers had failed due to the congealed soap, with some discharging a runny liquid. Most of the soap dispensers stopped functioning completely, but all of them produced a foul-smelling odour that permeated the washroom.

Customers complained about the smell and lack of soap in the reservoirs – this was due to the low viscosity from contamination which caused the soap to deplete faster. As a result, the soap systems needed replacing, causing a negative experience for customers as there was no soap available to them in the meantime.

The only temporary solution to relieve the pressure they were receiving from disgruntled customers would be providing freestanding soap dispensers or alternative dispensers stuck to mirrors or walls. However, this solution would taint the aesthetic appeal of their washroom.

Although our client was aware they had insisted on the bulk fill dispensers, the pressing question we were asked was, “Why did we knowingly sell a soap system that has the potential to fail, and why do we continue to do so?”

Why does Dolphin continue to sell liquid and foam soap refill systems?

The multifeed system is not a bad soap dispensing product, and there are bulk refill systems in commercial washrooms that are still reliable, in good condition and functioning. It is the most cost-effective option on the market and is a popular choice for clients who want to keep their initial costs down. Other benefits for our clients: there is flexibility to change soap and soap suppliers, the plastic soap tanks are recyclable, and soap refill dispensers are compliant with WELL standards — provided they are adequately cleaned and maintained.

The soap will not necessarily congeal in the reservoirs and damage the soap dispensers, but clients must be prepared to implement a robust maintenance regime to reduce the risk.

The problem exists no matter which washroom company supplies bulk fill dispensers. It is up to the facilities teams or janitorial service providers to commit to servicing the dispensers at regular intervals.

Commercial washroom using cartridge soap dispenser


Our integrity does not allow us to supply sub-par washroom products that will cause disasters for our clients and that is why we choose to be transparent and advise our clients about all the potential risks that may occur due to an inadequate maintenance regime.

Option 1:

Our advice – choose a sealed cartridge system as it is the best way to remove the topping up process that exposes the soap to contaminants and risks exponential microbial bacteria growth. A higher level of hygiene and reduced risk of congealing means the system and attached soap dispensers will maintain a higher efficiency for longer and require less maintenance. A sealed cartridge system also complies with WELL standards.

It is without a doubt that cartridge soap is the most reliable and effective solution because the system is completely sealed and significantly reduces the possibility of bacterial contamination. The initial cost may not fit the budget, but the ongoing expense is far more economical than bulk fill dispensers.

Upon soap depletion, connecting a new cartridge is quicker, cleaner and avoids spillages that may occur when decanting bulk fill soap from one container to another.

Option 2:

If the multi-feed system is still the preferred choice, then we are more than willing to offer training to the facilities teams, free of charge. Our Client Relations Executives will go onsite and show the facilities team how to perform the cleaning procedure and advise what maintenance they should do daily, weekly, monthly, and quarterly. We will also provide documented instruction sheets and videos for future reference.

Ultimately it is up to the janitorial service provider and facilities team to ensure they have a robust maintenance regime but the ongoing labour costs to maintain or fix failed bulk fill systems are certainly uneconomical.

Option 3:

The use of antibacterial soap with a chemical additive can help to prevent bacterial production, however, these soaps tend to be harsher to the users and cost more than regular liquid or foam soap.

Learn more about Bulk fill and Multifeed Soap Systems vs the Cartridge Soap Dispensing System.