On-site generation or bulk chemicals? An operating decision
Producing disinfectant on site offers three core advantages over buying ready-made chemicals: hazardous-goods transport and storage disappear, the solution is always fresh and at full efficacy, and the operating input reduces to salt and electricity. The advantage of ready-made chemicals is a low initial investment; on-site generation wins on total cost of ownership at medium and large scale.
There are two ways to meet a facility’s disinfectant need: buying ready-made chemicals or producing the disinfectant on site. The decision is not just a matter of the initial figure; safety, continuity, efficacy and total cost must all be weighed together.
The chain of ready-made chemicals
In the traditional method, disinfectant — usually sodium hypochlorite — is bought in drums or tanks. This means a chain in the background:
- Supply: continual dependence on ordering and delivery.
- Transport: hazardous-goods transport rules and cost.
- Storage: a suitable, ventilated and safe store; permit requirements.
- Loss of efficacy: sodium hypochlorite degrades over time; it weakens as it waits, and undesirable by-products such as chlorate can accumulate.
Every link in this chain is a cost and a risk item.
The logic of on-site generation
In on-site generation the facility produces its own disinfectant. The only thing kept in store is salt; the remaining input is electricity. The consequences of this structural difference:
- Safety: hazardous chemical transport and storage disappear.
- Freshness: the solution is produced at the moment of need, with no loss of efficacy from shelf life.
- Continuity: dependence on supply-chain interruptions is reduced.
- Efficacy: hypochlorous acid produced at neutral pH offers higher disinfecting power than ready-made hypochlorite at the same chlorine level.
How is the cost comparison made?
The right comparison is not “price per litre of chemical” but total cost of ownership. This calculation includes:
- On the ready-made side: unit price + transport + storage + safety infrastructure + the extra consumption caused by loss of efficacy.
- On the on-site side: system investment (once) + salt + electricity + maintenance.
For facilities with continuous, defined-volume consumption, the per-litre operating cost of on-site generation is markedly lower than ready-made chemicals. The system investment is generally recovered within a few years through operating savings.
Which for which facility?
- On-site generation is generally advantageous for pools, drinking-water facilities, food operations, healthcare facilities and industrial plants that consume disinfectant continuously.
- Ready-made chemicals may be more practical for very low, irregular, small-scale use.
The decision is made according to the facility’s consumption profile, safety requirements and growth expectations. The right approach is to place the total cost of the two scenarios side by side with a water analysis and a consumption assessment.
If you’re not ready to install a system yet
This comparison mostly answers the question “if you’re going to install your own system.” But not every facility is ready for that investment right away — a temporary need, small-scale use, or a bridge until installation is complete may call for something else.
For these cases, Skytech Water also supplies the same NIMBUS-grade hypochlorous acid solution directly — in 10–20 litre containers or by tanker, in whatever volume you need. This keeps your disinfection need covered without interruption, both before you move to on-site generation and during the transition.
What happens to chemical in storage: the measured data
“It degrades over time” gets said a lot in this discussion and documented rarely. Here is the documented version.
Stanford and colleagues examined stored sodium hypochlorite solutions in a study written for water utilities. The finding: after manufacture, while sitting in storage, oxyhalide species — chlorate, bromate and perchlorate — form within the solution. The factors setting the rate of formation were identified as temperature, ionic strength, hypochlorite concentration and the presence of transition metal ions.1
This means bulk chemical is a two-sided problem: active chlorine content falls while the unwanted by-product load rises. Product sitting in storage does not merely weaken — it progressively carries more oxyhalide.
The same study’s practical conclusion is equally clear: with proper manufacture, storage conditions and handling, this formation can be minimised. But what that means for a facility using bulk chemical is taking on temperature-controlled storage and stock-rotation discipline as an operating burden.
On-site generation removes the equation entirely, because there is no hypochlorite stock being stored. The only thing in the store room is salt, and salt does not degrade.
The by-product side
Disinfection by-products do not only arise from storage; those forming in the water itself must be accounted for. The reference review in this field establishes that by-product formation tracks the disinfectant’s dose and its contact time with organic matter.3
The operating consequence reaches past the cost table: being able to deliver the required dose at the right point, and no more than required, is a water-quality question and not only an efficiency one. A system generating on demand makes that control structurally easier.
Where the method sits in the literature
Industrial use of electrolyzed water is not a new claim. A peer-reviewed review covering the food industry records as its conclusion that the method’s only chemical input is salt, that generation can take place at the point of use, and that it offers cost and environmental advantages over conventional cleaning systems.2