Two Questions That Come Up More Than You'd Think
We hear these two fairly regularly:
"How long does Blop last before it expires?" "I just received my Blop and there's something white and flaky on the surface. Is it mouldy?"
They're both completely reasonable things to wonder about. Let's answer them properly.
How Long Does Blop Last?
Blop has a recommended best-before period of three years from the date of manufacture. That's the window where we're confident the formula is performing at its best.
That said, Blop's gel is alkaline in nature, and alkaline formulas tend to be inherently stable. As long as Blop is stored sensibly, it can remain effective well beyond that three-year mark. There's no dramatic chemical breakdown waiting to happen.
What "stored sensibly" actually means:
- Keep it somewhere dry, away from persistent humidity
- Avoid leaving it in direct sunlight or anywhere it'll be exposed to prolonged heat
- Don't store it unsealed or in contact with other cleaning products
A bathroom cabinet, a laundry cupboard, or a cool dry shelf is perfectly fine. You don't need to do anything special.
That White Flaky Stuff Is Not Mould
This one catches people off guard, and we understand why. You open a new Blop, see some white crystalline patches on the gel surface, and your first thought is that something's gone wrong.
It hasn't.
When this was first raised by customers, we went straight to our manufacturer and the independent laboratory that tests Blop's formula. Their conclusion was clear and unambiguous: it is not mould.
Here's the reason we can say that with complete confidence.
Why Mould Cannot Grow on Blop
Blop's formula is alkaline. Mould requires an acidic or neutral environment to survive and grow. An alkaline environment is simply not somewhere mould can take hold.
This is the same reason Blop is safe for the rubber seals, plastic valves, and internal fittings inside your cistern. It contains no acids, no harsh bleach, and nothing corrosive. The alkalinity is actually a protective quality.
So if you're ever wondering whether what you're looking at could be mould, the chemistry of the product itself rules it out.
So What Is That White Stuff?
What you're seeing is called surfactant bloom.
Surfactants are the cleaning agents in Blop's formula. When the gel surface is exposed to air, either during packaging, transit, or storage, the surfactants can migrate to the surface and form small crystals. Sometimes a tiny airborne dust particle is enough to trigger the process.
It looks a little strange, but it's a completely natural physical phenomenon. It has no effect on cleaning performance, no effect on safety, and the moment the gel contacts water inside your cistern, those crystals dissolve entirely.
Think of it a bit like the fine white layer that sometimes forms on dark chocolate after a temperature change. It looks like something went wrong, but it's just the chemistry doing what chemistry does.
What's in Blop's Formula
For those who want the full picture, here are Blop's key ingredients:
Ethoxylated Alcohols — the primary surfactants responsible for cleaning. These are also the compounds most likely to form surface crystals (surfactant bloom) when exposed to air.
Sulfonic Acids, sodium salts — mild cleaning agents that work alongside the surfactants.
CI 42090 — the blue colourant that tints your flush water and acts as a visual indicator of how much gel is remaining.
Fragrance — a light, fresh scent designed to complement rather than overpower.
Ethoxylated Sorbitan Monostearate — a stabiliser that maintains the gel's consistency.
Sorbitan Triolate — an emulsifier that keeps the formula evenly blended.
Polyquat 149 — a conditioning agent that supports the gel's release over time.
Chloroxylenol — an antimicrobial agent that helps keep bacterial growth in check inside the cistern.
Phenoxyethanol — a preservative that keeps the formula stable.
Propylparaben — a second preservative working alongside Phenoxyethanol.
This is an alkaline, non-acidic formula. There is nothing in it that would support mould growth, and nothing that would corrode your cistern components.
In Short
- Blop's recommended best-before period is three years from manufacture
- Stored properly, it can remain effective beyond that
- White crystalline patches on the surface are surfactant bloom, not mould
- Mould cannot grow on Blop because the formula is alkaline
- Surfactant bloom dissolves completely on contact with water and has no effect on performance
If you ever receive a Blop and something doesn't look right, feel free to reach out at crap@blop.today. We're always happy to take a look.
Common Questions About Blop's Shelf Life and Surface Appearance:
Does Blop have an expiry date?
Blop has a recommended best-before period of three years from the date of manufacture. Because the formula is alkaline and chemically stable, it can remain effective beyond this period when stored correctly in a cool, dry place away from direct sunlight.
How should I store Blop before use?
Keep it in a dry location away from direct sunlight and high humidity. A bathroom cabinet or laundry cupboard is ideal. There's no need for refrigeration or any special conditions.
Is the white stuff on my Blop mould?
No. What you're seeing is surfactant bloom, a natural phenomenon where cleaning agents in the gel migrate to the surface and form small crystals when exposed to air. It's purely cosmetic and dissolves completely once the gel contacts water.
Can mould grow on Blop?
No. Blop's formula is alkaline, and mould requires an acidic or neutral environment to grow. The alkalinity of the gel makes it an environment where mould simply cannot survive.
Does surfactant bloom affect cleaning performance?
Not at all. The crystals dissolve immediately when they come into contact with water, and the cleaning formula performs exactly as intended. There is no impact on effectiveness.
Is Blop safe if it has surfactant bloom on the surface?
Yes, completely. Surfactant bloom is a cosmetic variation with no safety implications. Your cistern and its components are not at any risk.
Why is Blop's alkaline formula significant?
An alkaline formula means Blop contains no harsh acids or corrosive substances. This is why it's safe for rubber seals, plastic valves, and internal cistern fittings, and also why it cannot support mould growth.
What causes surfactant bloom?
Surfactant bloom occurs when cleaning agents in the gel are exposed to air and migrate to the surface, sometimes triggered by tiny airborne dust particles during packaging or transit. It's a natural physical process, not a sign of contamination or spoilage.