Ask Me Anything!


Sugru's Formulation Chemist, Vivian Christogianni

We like to think we’re a friendly bunch at Sugru HQ. No secrets, no dramas, just commitment to the cause and a couple of tra-la-las. So after launching our new Family-safe | Skin-friendly Formula, we thought it would be useful and fun to compile some initial questions that you guys had about the new formula. Then we put them to one of the clever scientists in the team here, who developed it. 

Meet Vivian, awesome formulation chemist by day and regular gig goer by night. 

You taking notes? Let’s go….

Q: What’s the difference between Original Formula Sugru and Family-safe | Skin-friendly Formula Sugru?

From a user’s point of view, very little... but from a formulation aspect, quite a lot!

So as far as most users are concerned, Original Sugru and Family-safe | Skin-friendly Sugru perform in more or less exactly the same way - which is what we intended. A Sugru superuser might notice three very subtle differences... Firstly, Family-safe | Skin-friendly Sugru has a slightly nicer smell and secondly comes out of the pack a little easier than Original Sugru. The third small difference is the cure time. You might get away with a slightly shorter curing time with Original Sugru whereas we would recommend you abide by the full 24 hours when using the new Family-safe | Skin-friendly Formula. It cures 2mm deep in 24 hours, so thicker layers can take a bit longer to set in the middle. And that’s it!

From a formulation point of view the differences between Original Sugru and Family-safe | Skin-friendly Sugru are small, but important. The main components are exactly the same but a huge change has been made to the cure system which controls how the material changes into silicone rubber after you open the pack.  We are using a completely new cure system, a change which is ultimately what makes it kinder to your skin.

Q: Is Original Sugru stronger in any way?

In a word - no. Our Original Formula cures a little quicker so it develops its strength quicker but this does not mean that it is stronger once both are fully cured. We generally recommend using Sugru for attaching and hanging objects that weigh up to 2kg and this is for both formulas. We know Sugru can hold more but this is heavily dependent on the design and what materials you're bonding.

Q: Is Original Sugru harder than Family-safe Sugru? 

Both Original and Family-safe | Skin-friendly Sugru have a similar hardness once cured, but it’s fair to say that the Family-safe | Skin-friendly Sugru takes a little longer for the full hardness to develop.

Q: What does the 30 - 45 mins working time mean? How long do I have, and how do I know when the time is up?

This is a helpful guide. The exact working time is actually influenced by environmental factors like the temperature and humidity when opening a pack. The warmer and more humid it is, the less time you have before the surface will start to set. Both formulas give you a minimum of 30 minutes, and in some cases it can be re-worked a little beyond 45 minutes. It’s a good idea not to continue to reshape it after 45 minutes as there's an increasing risk that the surface will start to cure and not be as easy to smooth and perfect.

Q: By its very name the Family-safe | Skin-friendly formula implies that Original Sugru is damaging to your skin and unsafe for kids. Is this true?

No - it’s not quite that simple - but Original Sugru does contain ingredients classified as skin sensitisers in small amounts. This restricts it to use by grownups. It’s made clear on the back of pack and basically means that allergic reaction is possible. That said, we’ve sold over 14 million packs and have had almost no reports about this. The Family-safe | Skin-friendly Formula does not contain any ingredients that are sensitising, which is why we say it’s kinder to your skin.

Q: Do you add fragrance to the Family-safe | Skin-friendly Formula?

No, we don’t add any fragrance to the product. I quite like how it smells!

Q. So if the new Family-safe | Skin-friendly Formula is suitable for unsupervised use by children from 8 years of age,  why do children from ages 3-8 need to be supervised when using it? 

According to regulatory guidelines, children under 8 are best supervised with most creative materials like Sugru, as they may use it in ways that it’s not intended for. We recommend that younger children are supervised so that an adult can be aware if any of the product transfers onto clothes, play surfaces or soft furnishings. These should be cleaned up at the end of the creative session, as the material may become more difficult to remove completely from fabrics and carpets if left to cure overnight. It’s mainly for this reason why we advise some sort of adult supervision.

Q: Does the Family-safe | Skin-friendly Formula have a longer shelf-life?

Currently no... but watch this space. Our top tip for making your Sugru last longer is to keep it in the fridge, which can extend the life by up to three times. This rule of thumb applies to both formulas. 

Q. What was the biggest challenge in developing the new Family-safe | Skin-friendly Formula?

Matching the behaviour of Original Sugru was by far the biggest challenge and triumph. To launch a product that met strict child safety regulations whilst performing like the original was no mean feat... and something we’re all really proud of, especially those of us in the R&D team who had to come up with a lot of technical solutions to make this possible!

Some of the awesome scientists from our R&D team: Reya, Vivian and Tom