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Sanitary grade, or it goes black in a season

The best sanitary silicone and seals for 2026

The word that matters on a cartridge is sanitary, and it means the sealant carries a fungicide intended for permanently damp joints. Ordinary construction silicone in a shower goes black at the edges within a season, and no amount of cleaning brings it back — the growth is inside the bead. The second word is the chemistry. Acetoxy silicone smells of vinegar, cures fast and cheap, and can corrode some metals and stain natural stone; neutral cure costs more and is what marble and mirror backs need. MS polymer is the third option: it sticks to more, takes paint, and does not have silicone's permanent oil residue — which matters, because nothing sticks to a joint that has had silicone in it, including new silicone, unless the old bead is fully removed. Read the skin time if you are working alone, since it is how long you have to tool the bead. We compare chemistry, whether a fungicide is stated, skin and full cure time, joint width range, colour range, and whether it takes paint.

What we recommend

  1. fischer premium sanitary silicone cartridge in white, 310 ml

    fischer Premium sanitary silicone, 310 ml, white, fungicidal

    The largest and cheapest cartridge in this hub, with a fungicide and a claim about surviving cleaning — and not one cure time.

    Chemistry
    Not stated as a chemistry — described as a sanitary silicone
    Fungicide stated
    Yes — a fungicidal formulation, stated
    Skin time
    Not stated by the maker
    Full cure time
    Not stated by the maker
    Joint width range
    Not stated by the maker
    Colours
    White — this cartridge; no range is stated
    Paintable
    Not stated by the maker
    Amazon reference
    B000UW8LPE (same reference on 6 Amazon marketplaces)
    EAN
    4006209531013
    • 310 ml, the largest cartridge in this hub, at the lowest price
    • States high abrasion resistance, which is what a joint has to survive when it is scrubbed weekly
    • No skin time and no full cure time, so when the joint can be smoothed and when you can shower is unknown

    Best for: A long run of joints — a bath, a shower tray and a worktop in one session — where the cartridge should not run out.

    ≈ £8 / 7 €
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  2. OTTOSEAL S 100 premium sanitary silicone cartridge in white

    OTTOSEAL S 100 premium sanitary silicone, acetoxy, 84 colours

    The best-specified sealant in this catalogue: a named chemistry, a movement figure, an emissions class and a colour range that will match your grout.

    Chemistry
    One-component acetoxy-cure silicone — stated
    Fungicide stated
    Yes — fungicidal and bacteriostatic properties, stated
    Skin time
    Not stated as a figure — the maker states a short thread-pull, which means it can be worked without pushing back
    Full cure time
    Not stated by the maker
    Joint width range
    Not stated as a range — the maker states 50 % movement capability
    Colours
    84 colours including 10 matt shades — stated; this cartridge is C01 white
    Paintable
    Not stated by the maker
    Amazon reference
    B009B6HL0Q (same reference on 6 Amazon marketplaces)
    EAN
    4030574038570
    • Names the chemistry — one-component acetoxy — which is the fact that decides where it can be used
    • States 50 % movement capability, the figure that decides whether a joint cracks as a bath flexes
    • Acetoxy cure releases acetic acid and is not the right choice on every metal or natural stone

    Best for: A joint that has to match coloured grout, or one that will move — a bath that fills and empties every day.

    ≈ £12 / 9 €
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  3. Soudal sanitary silicone cartridge in white, 300 ml

    Soudal sanitary silicone, 300 ml, five-year mould protection guarantee

    The only sealant here that puts a number of years on its mould resistance — which is exactly how a bathroom joint fails.

    Chemistry
    One-component silicone — stated; the cure type is not named
    Fungicide stated
    Yes — with a stated five-year mould protection guarantee
    Skin time
    Not stated by the maker
    Full cure time
    Not stated by the maker
    Joint width range
    Not stated by the maker
    Colours
    White — this cartridge; no range is stated
    Paintable
    Not stated by the maker
    Amazon reference
    B06XRF8FVC (same reference on 4 Amazon marketplaces)
    EAN
    5411183087224
    • A five-year mould protection guarantee — the only sealant in this hub to attach a duration to its fungicide
    • Adhesion named specifically on stainless steel, aluminium, glass, ceramic and porcelain
    • The cure type is not named, so where it should not be used cannot be judged

    Best for: The joint between a bath or shower tray and the wall, in a bathroom where the joint has gone black before.

    ≈ 10 €
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  4. Sika Sikasil C sanitary silicone sealant cartridge in white

    SIKA Sikasil C sanitary sealant, 300 ml, non-corrosive and primerless

    A non-corrosive sealant that suits metal and acrylic where acetoxy silicone is risky — and it does not state a fungicide, which matters in a shower.

    Chemistry
    Not stated as a chemistry — the maker states it is solvent-free and non-corrosive
    Fungicide stated
    Not stated by the maker — the other three sealants in this hub all state one
    Skin time
    Not stated by the maker
    Full cure time
    Not stated by the maker
    Joint width range
    Not stated by the maker
    Colours
    White — this cartridge; no range is stated
    Paintable
    Not stated by the maker
    Amazon reference
    B01MDSUKFH (same reference on 5 Amazon marketplaces)
    EAN
    3240240016028
    • Stated non-corrosive, which is what makes it safe against metals that acetoxy silicone can attack
    • No primer needed on most substrates, and named for glass, metal, wood, acrylic, polycarbonate and ceramic tile
    • No fungicide is stated, and the other three sealants in this hub all state one

    Best for: Sealing against an acrylic bath, a polycarbonate screen or a metal edge, where an acetoxy silicone would be the wrong choice.

    ≈ 11 €
    Check price on Amazon