# Dispensers

A dispenser is a reservoir plus a metering mechanism: a manual pump, a foaming pump, or a battery-run touchless sensor. The mechanism matters less than whether its refill is sealed or open, because open bulk-fill reservoirs are the ones studies keep finding contaminated with bacteria, and, for hand sanitiser, losing alcohol strength to evaporation.

## How it works

Every dispenser is a sealed or semi-sealed reservoir with a metering mechanism on top. A manual pump pulls liquid up a dip tube with a spring-loaded piston and a one-way ball valve: pressing the actuator draws liquid up, and releasing it reseals the tube against backflow. A foaming pump adds a chamber that mixes air into the liquid as it passes, so the same stroke gives less liquid but more lather. A touchless dispenser swaps the actuator for an infrared, photo or radar sensor wired to a small motor that fires a preset dose, on disposable or rechargeable batteries. A rarer family, the soap mill, grates a bar of soap into flakes instead. None of this decides quality on its own; what decides it is whether the reservoir refills through an open pour or a sealed cartridge or pouch. [1]

| Family | What it is | Suits |
|---|---|---|
| Manual pump | A dip tube, spring and one-way valve that you press by hand; no power, nothing to charge. | everyday hand soap, lotion and dish soap bottles |
| Foaming pump | A second chamber mixes air into the liquid so the same fill stretches over more washes as foam. | hand soap where people want less liquid used per wash |
| Touchless sensor | An infrared, photo or radar sensor triggers a small motor to release a preset dose with no button pressed. | shared bathrooms and kitchens where hands-free matters |
| Soap mill | Grates or grinds a bar of soap into flakes or powder as it is turned, instead of pumping liquid. | rare in home listings; common in German public washrooms |

## How an expert narrows the choice

```mermaid
timeline
  section 1 · What it dispenses
    shower (shampoo, conditioner, body wash) : ask Chambers
  section 2 · How it dispenses
    touchless sensor : ask Power source, Dose control
    manual pump / foaming pump : skip Power source
  section 3 · Refill system
    Pour soap straight in, or load a sealed refill?
```

1. **What it dispenses.** Hand soap, dish soap, lotion, sanitiser, or shower products?
   What goes in decides counter versus shower mounting and single versus multi-chamber, and is the one answer every buyer already knows before they start shopping.
   If shower (shampoo, conditioner, body wash): ask Chambers.

2. **How it dispenses.** Manual pump, foaming pump, or touch-free sensor?
   Manual, foaming and touchless sort the catalog by how much the dispenser costs, whether it needs power, and how many hands touch the actuator.
   If touchless sensor: ask Power source, Dose control.
   If manual pump or foaming pump: skip Power source.

3. **Refill system.** Pour soap straight in, or load a sealed refill?
   Open versus sealed refill is the one fact three independent studies actually measured, and it is what a contaminated or evaporated dispenser really costs you.
   Skip if already known: an earlier answer naming a specific proprietary cartridge or pod system.

## What to surface

### What it dispenses

The liquid the dispenser is built to hold: hand soap or lotion, dish soap, hand sanitiser, or shower products. What goes in decides the form factor. Hand soap and lotion sit in a counter pump; dish soap mounts through the sink deck; hand sanitiser is the one liquid where an open reservoir is a measured chemical risk, since its alcohol evaporates over time in dispensers without an internal seal; shower products come in multi-chamber wall units built for two to four liquids at once. [1] [12] [7]

Values: hand soap or lotion, dish soap, hand sanitiser, shower (shampoo, conditioner, body wash).
Question to ask: Hand soap, dish soap, lotion, sanitiser, or shower products?

Used as: top-level split, filter. Data: derived from listing fields, backfill cost low. Look for it as: Not usually a field. Derive from the listing's own title and type words (soap, lotion, sanitiser, shower, shampoo).
Map listing title and category words; default a plain single-chamber counter pump with no other signal to hand soap or lotion.

### How it dispenses

The action that releases a dose: a hand-pressed pump, a foaming pump, or a battery-run touchless sensor. Soap mills are a separate, rare mechanism, out of scope for this enum. A plain pump needs no power and nothing to break electrically, but every user presses the same actuator everyone else has touched. A foaming pump stretches the same fill into more washes by mixing in air, at the cost of a lather some people find thin. A touchless sensor removes hand-to-pump contact, which studies link to a different, smaller hygiene factor than the one that actually drove measured contamination: the pump's own pressure-release valve. [1] [2]

Values: manual pump, foaming pump, touchless sensor.
Question to ask: Manual pump, foaming pump, or touch-free sensor?

Used as: top-level split, filter. Data: derived from listing fields, backfill cost low. Look for it as: Usually in the title or bullets ('foaming', 'touch-free', 'sensor', 'automatic'); plain pumps are rarely labelled, so treat an unlabelled listing as manual.
Keyword match the title; default to manual pump when none of the other two are named.

### Refill system

Whether you pour soap or sanitiser straight into an open reservoir, or load a sealed cartridge or pouch. Three studies found the same pattern: pouring soap or sanitiser straight into an open reservoir runs dirtier, and for sanitiser weaker over time, than refilling a sealed cartridge or pouch. One study measured about one in four public-restroom bulk dispensers contaminated and a 26-fold rise in hand bacteria after washing with them, against a 2-fold fall with sealed refills, a figure no other cited study repeats. Sealed costs more per ounce and locks you to one brand. [3] [4] [5]

Values: open (pour soap in), sealed cartridge or pouch.
Question to ask: Pour soap straight in, or load a sealed refill?

Used as: top-level split, filter, shown on the card. Data: needs research, backfill cost low. Look for it as: Almost never stated directly. A named cartridge, pod or pouch refill in the title or bullets means sealed; a plain pump bottle with no such name defaults to open.
Default to open for any plain pump bottle; flip to sealed only when the listing names a specific proprietary refill format.
Chart: Hygiene vs cost-per-use map.

### Chambers

How many separate liquids the dispenser holds and releases at once, from one to four. A shower holds shampoo, conditioner and body wash at minimum, and a single-chamber pump means juggling three separate bottles on a wet shelf. A 2 to 4 chamber unit holds that whole routine in one wall- or suction-mounted piece, at the cost of needing all of it to run out and get refilled at different rates. [12]

Range: 1 to 4 count. 1 for soap, lotion, dish soap and sanitiser; 2 to 4 for shower dispensers.
Question to ask: One bottle, or two to four in one unit?

Used as: filter, shown on the card. Data: needs research, backfill cost low. Look for it as: In the product title itself on Better Living's own site, e.g. 'Shower Dispenser 3 Chamber'; unconfirmed on independent retail listings (Amazon, Home Depot, Grainger all blocked fetches), so treat as researched rather than assumed-listing.
Read directly from the title when it matches a known brand's naming convention; default to 1 for anything not named as a multi-chamber shower unit.
Chart: count of filled icons, one per chamber.

### Power source

How a touchless dispenser's sensor and pump get power: disposable batteries, or a built-in rechargeable battery. A touchless sensor needs power from somewhere. Disposable batteries are cheap to replace anywhere but die without warning mid-wash and add to landfill; a built-in rechargeable needs a cable and a reminder to charge it, but nothing to buy and throw away. [10] [11] [12]

Values: disposable batteries, rechargeable battery.
Question to ask: Swap batteries, or recharge it?

Used as: filter, shown on the card. Data: needs research, backfill cost low. Look for it as: Usually in the bullets ('4 AA batteries required', 'rechargeable', 'USB charging'); only applies to touchless listings.
Brand spec pages state it for every touchless model found; null for manual and foaming pumps.

### Capacity

How much liquid the reservoir holds, in millilitres (or fluid ounces). A bigger reservoir means fewer refills, but only up to a point: a 500+ ml touchless station takes longer to use up than a 250 ml counter pump, so it sits full for longer, which is exactly the condition under which an open hand-sanitiser reservoir loses the most alcohol to evaporation before you get to the bottom of it. [10] [12]

Range: 200 to 530 ml. most countertop and touchless units run 200 to 300 ml; touchless stations and some shower caddies go up to about 530 ml.

Used as: filter, shown on the card, sortable. Data: needs research, backfill cost low. Look for it as: Often in the title as an oz or ml figure when sold as a single branded unit ('9 fl oz', '300 ml'); frequently missing on generic marketplace listings.
Brand spec pages state it reliably; backfill from there where the listing omits it.
Chart: position on a horizontal ml scale.

### Dose control

Whether a touchless dispenser's per-press dose is fixed or can be adjusted. A fixed-dose touchless unit always releases the same amount, which can be more than a quick rinse needs. An adjustable one lets you dial down the volume or just hold your hand closer to the sensor, cutting refill waste over time at no extra running cost. [12] [10]

Values: fixed dose, adjustable dose.
Question to ask: Fixed dose, or adjustable?

Used as: filter, shown on the card. Data: needs research, backfill cost low. Look for it as: Rarely stated on generic listings; touchless brand pages describe it in bullets ('adjustable', 'dial') or as hand-distance control. Only applies to touchless sensor units.
Brand spec pages state it for touchless models found; default to fixed dose when unstated, null for manual and foaming pumps.

## Numbers worth computing

| Metric | Formula | Why |
|---|---|---|
| Cost per use (price per ml) | `refill_price / capacity_ml` | Tells you whether a bigger refill actually saves money, but it only means anything when refill_system is open; a sealed cartridge locks you to one brand's price. [12] |

## What you give up

- A sealed cartridge or pouch avoids the bacterial and evaporation problems open refill shows, but costs more per ounce and locks you into one maker's refills. [3] [4] Board branch: "See more sealed-refill dispensers".
- Touch-free removes one point of contact and doses consistently, but needs batteries or charging that a plain pump never does, and costs more up front. [2] [10] Board branch: "See more manual pump dispensers".
- A bigger reservoir means fewer refills, but an open hand-sanitiser reservoir loses the most alcohol to evaporation while it sits half-used for weeks on end. [5] Board branch: "See more sealed or smaller dispensers".

## How to draw it

**Hygiene vs cost-per-use map** (two axis map, shows Refill system, cost_per_use). Plots dispensers with refill_system on one axis and cost_per_use on the other, so a buyer sees the sealed-but-pricier cluster against the open-but-cheaper one at a glance. This is a proposal, nobody draws it this way yet.

## Words you will meet

- **Dip tube**. The tube inside a pump bottle that carries liquid from the bottom up to the pump when you press it.
- **Actuator**. The button on top of a pump that you press down to release a dose.
- **Pressure-release valve**. The one-way valve inside a pump that lets it reseal; studies trace contamination to this part, not to who touches the actuator.
- **Foaming pump**. A pump with a second chamber that mixes air into the liquid so it comes out as foam, not liquid.
- **Touchless (sensor) dispenser**. A battery-run dispenser that releases a dose when a sensor detects your hand, with no button to press.
- **Sealed refill**. A closed cartridge or pouch you snap in, as opposed to an open reservoir you pour soap into yourself.
- **ABHS (alcohol-based hand sanitiser)**. A sanitiser the CDC considers effective at 60% alcohol or higher, for when soap and water aren't available.
- **Soap mill**. A grater or grinder that turns a bar of soap into flakes as you turn it, instead of pumping liquid.

## Where we made a call

- Bulk-refillable soap dispensers run meaningfully dirtier than sealed-refill dispensers. (confidence high). Sources disagree. Zapka 2011 found about one in four public-restroom bulk dispensers contaminated; a 2023 German hotel-room study found 70.2% of refillable pumps contaminated against 10.6% of sealed units. Same direction, different settings, different magnitude. [3] [4]
- Open, no-reservoir hand-sanitiser dispensers lose enough alcohol to evaporation to fall below an effective strength. (confidence high). PLOS ONE 2022 measured this directly in the lab and found subpotent ethanol in a meaningful share of field samples, worse under misuse. CDC's 60% floor is the strength being lost. [5] [6]
- Touch-free dispensing is marketed as the hygiene fix, but the measured contamination route is the refill seal, not touch. (confidence medium). Ours. Wikipedia's automatic-dispenser article claims touch-free 'eliminates' bacterial transmission with no citation; the 2023 German study traced contamination to the pump's pressure-release valve, present on touch and touchless pumps alike. [2] [4]
- Pediatric hand-sanitiser exposure is measured in the tens of thousands of cases a year in the US, not a handful. (confidence high). Sources disagree. NPDS: 95,718 cases aged under 19, 2017-2021, 93.9% by ingestion. AAPCC's own tracker separately counts 2,774 cases aged 0-12 as of Feb 2024; different ages, windows and methods, not a contradiction. [9] [8]

## References

1. [Soap dispenser](https://en.wikipedia.org/wiki/Soap_dispenser) (primer). Supports: Defines a soap dispenser and its main types: manual liquid, dry/mill, and foam.; Describes dip-tube pump parts and the press-release priming operation of a manual pump.; States soap mills grate bar soap into flakes; common in German public washrooms.; Describes foam pumps as mixing air and liquid through dual pumps to make lather.; Describes automatic dispensers as hands-free, battery-powered, usable for soap, sanitiser, shampoo or lotion..
2. [Automatic soap dispenser](https://en.wikipedia.org/wiki/Automatic_soap_dispenser) (primer). Supports: Describes radar, photo and passive-infrared sensor mechanisms used in touchless dispensers.; Claims touch-free dispensing eliminates bacterial transmission between users, without citing a source..
3. [Bacterial hand contamination and transfer after use of contaminated bulk-soap-refillable dispensers (Applied and Environmental Microbiology, 2011)](https://pubmed.ncbi.nlm.nih.gov/21421792/) (academic). Supports: About one in four public-restroom bulk-refillable soap dispensers are bacterially contaminated.; Washing with contaminated bulk soap raised hand bacteria 26-fold; sealed refills cut it 2-fold..
4. [A loophole in soap dispensers mediates contamination with Gram-negative bacteria (2023)](https://www.ncbi.nlm.nih.gov/pubmed/37877653) (academic). Supports: 70.2% of refillable pump dispensers were contaminated versus 10.6% of sealed-refill units, in hotel rooms.; Traces contamination to the pump's pressure-release valve, not to who touches the actuator..
5. [Presence of unsafe chemical impurities, accelerated evaporation of alcohol, and lack of key labeling requirements... (PLOS ONE, 2022)](https://pubmed.ncbi.nlm.nih.gov/35303018/) (academic). Supports: Open refillable hand-sanitiser dispensers without an internal reservoir let ethanol evaporate fastest, measured in the lab.; Subpotent ethanol was found in 9.09% and 82.05% of field samples, the higher figure tied to misuse..
6. [Clean Hands, About Hand Hygiene](https://www.cdc.gov/clean-hands/about/index.html) (regulator). Supports: States the CDC-recommended hand sanitiser alcohol floor of at least 60%..
7. [Hand sanitizer](https://en.wikipedia.org/wiki/Hand_sanitizer) (primer). Supports: Second source for the 60% alcohol floor and the 60-95% effective range.; States alcohol-based sanitiser is flammable and regulated by the FDA as an OTC drug..
8. [America's Poison Centers, Hand Sanitizer tracker](https://poisoncenters.org/track/hand-sanitizer) (other). Supports: Counts 2,774 hand-sanitiser exposure cases in children 0-12 as of February 2024.; States hand sanitiser should be kept out of reach of children at all times..
9. [Pediatric hand sanitizer exposures reported to United States poison centers, 2017-2021 (2023)](https://pubmed.ncbi.nlm.nih.gov/37358035/) (academic). Supports: Counts 95,718 pediatric hand-sanitiser cases 2017-2021, 93.9% by ingestion, mostly at home..
10. [simplehuman, Rechargeable Liquid Soap Sensor Pump, 9 fl. oz.](https://www.simplehuman.com/products/rechargeable-sensor-pump-9-fl-oz) (spec sheet). Supports: States this rechargeable touchless pump holds 9 fl oz and runs 4 months per charge.; States hand distance from the sensor controls how much soap is dispensed..
11. [simplehuman, Sensor Pump collection](https://www.simplehuman.com/collections/sensor-pumps) (spec sheet). Supports: Shows this brand's whole touchless line (9 and 14 fl oz) is rechargeable, none disposable-battery..
12. [Better Living Products, Dispensers collection and TOUCHLESS XL product page](https://betterlivingproducts.ca/collections/dispensers) (spec sheet). Supports: Gives capacities 200, 295 and 530 ml and '4 AA batteries required' for a touchless model.; Shows shower dispensers named and sold by chamber count: 2, 3 or 4 chambers.; States the TOUCHLESS XL's dial adjusts the volume of liquid dispensed per press..