The hidden chemistry of soft-plastic toys: from "squishies" to slime

What was the UK warning?

Trading Standards teams at Swansea and Glasgow councils warned that counterfeit "squishy dumpling" toys were releasing several VOCs — including styrene, ethylbenzene and xylenes. These toys often reek of chemicals/plastic straight out of the packet; short-term exposure can cause headaches, nausea, and skin and airway irritation, and because they're counterfeit and small there's also a choking risk.¹

What are VOCs, and why are they in soft-plastic toys?

VOCs (volatile organic compounds) are chemicals that evaporate — and smell — at room temperature. In cheap soft-plastic toys they usually come from low-grade plastic, adhesives, inks and solvent residue; that "new toy plastic smell" is often VOCs off-gassing.³

The one drawing most attention is styrene: in 2019 the International Agency for Research on Cancer (IARC) classified it Group 2A — "probably carcinogenic to humans".³ The immediate risk from brief everyday contact is mainly irritation (headaches, dizziness, nausea, eye/nose/throat and skin discomfort); long-term, repeated high exposure is a different matter.

Why are children more at risk?

• Mouthing and hands-to-mouth: squishies and slime are made to be squeezed, kneaded and chewed — more exposure routes (skin, mouth, inhaling the smell) than for adults.
• Smaller airways, higher intake per body weight: in the same room, children inhale a larger share of airborne VOCs than adults.
• Sensitive developmental windows: boron and some chemicals raise reproductive/endocrine-development concerns, where the impact can be longer-lasting.²

Not just squishies: slime had a comparable problem

In 2019, Hong Kong's Consumer Council tested 20 slime and clay toys and found 12 (7 in 10) exceeded the European toy-safety standard EN71-3's recommended boron migration limit (300 ppm), the worst by over 12×. Moderate-to-high boron intake can cause nausea and vomiting, with a longer-term reproductive-health concern. The same tests found 12 samples containing MIT/CMIT preservatives, 5 over the EU limit, which can cause skin allergy.²

To be clear: slime's main issue is boron and preservatives, not the same chemical as the squishy VOCs. But both point to one thing — cheap soft novelty toys are an easily-overlooked source of children's chemical exposure. European consumer groups continue to push the EU to tighten the boron limit in toys.⁴

One practical thing in common: the smell

Both toy types share a very practical warning sign — a sharp chemical/plastic odour. A legitimate toy shouldn't reek the moment you open it. A strong smell, a sticky feel, and no safety marking at all on a rock-bottom-price soft toy are red flags.

What parents can do

1. Smell it: if a squishy / clay / slime reeks of chemicals out of the packet, don't let kids play with it — especially not against skin for long or near the mouth.
2. Check the label: choose toys with CE / UKCA / a toy-safety mark and brand + ingredient labelling; avoid unlabelled, rock-bottom-price items from marketplace sellers.
3. The younger the child, the more caution: no slime / small squishies for under-3s (choking + mouthing risk); always wash hands after slime.
4. Air it out: if a new toy smells of plastic, unwrap and air it for a few days; keep the room ventilated during play.
5. No need to panic — just choose: the issue isn't "all soft-plastic toys are toxic", it's the cheap, cross-border, uncertified batch. Spend a little more on ones that were vetted.

The bottom line

From squishies to slime, the story rhymes: the cheapest, most strongly-scented (that's the chemicals), most garishly-coloured soft toys are often where the risk sits. What parents do is small — smell it, check the label, buy certified — and it steers you clear of most of the exposure you can't see.

Sources