What symptoms indicate overexposure to isocyanates?

Overexposure to isocyanates can show up in a few different ways, and the symptoms might seem mild at first — but they can get worse quickly with continued exposure. The most common warning signs include:

• Irritated eyes, nose, and throat – this might feel like hay fever or a cold

• Coughing, wheezing, or shortness of breath

• Chest tightness – especially after work or during exertion

• Skin rashes or itching – some isocyanates can cause allergic skin reactions

• Headaches, fatigue, or general malaise

In more serious cases, workers can become sensitised, which means their bodies react strongly even to very low levels. This can lead to occupational asthma, which is often irreversible. Sometimes symptoms don't show up until hours after exposure, so they can be easy to miss or misattribute.

If someone’s showing these symptoms and they’re working around isocyanates, it’s important to investigate quickly — exposure limits are low for a reason.