【Haichuan Corrosion Prevention Knowledge】How dangerous are solvents? Many people only focus on fire protection, ignoring the even more deadly threats

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Those who work on construction sites are familiar with thinners. Most people know: it catches fire easily. But the truth is—many people don’t even understand what it does. I previously wrote an article specifically explaining what diluents do and why they are added; those who are interested can take a look at it. Many people think it was this bucket of liquid that caught fire, but that’s not the case. 👉What catches fire is the gas emitted by it. As soon as the barrel is opened and its scent escapes, it fills the air. As long as the concentration is appropriate, it can catch fire upon contact with a heat source. There’s a common misconception here: it’s not the stronger the taste that makes it more dangerous, nor is it the case that no taste means it’s safe. 👉The situations where accidents are most likely to occur are actually those when there is a smell and people can still stay there. The flammability range of common diluents is roughly between 1% and 7% in air; below this concentration they will not ignite, while above this range they are less likely to burn. At first, the flavor is very mild and there isn’t enough vapor to ignite it ； Work for a while; as the flavor develops and one is still able to keep working, at that point one has actually entered a dangerous zone ； If one continues to work in silence like this, anger keeps building up, and once a source of fire is encountered, it can easily catch fire all at once. There’s another detail that many people don’t pay much attention to: the solvent liquid itself is lighter than water (the specific gravity of solvents is usually around 0.85 g/cm³), but the gases that evaporate from it are heavier than air, so they accumulate in areas such as the floor and corners. So it’s often the case that—standing up, it seems fine, but once you lower your head or go to the corners, the smell becomes much stronger. 👉It’s not the liquid that flows downward; it’s the gas that accumulates in lower areas. Several common dry methods used on site are nothing new: they are employed in enclosed or semi-enclosed spaces, with a door being opened to facilitate ventilation ； Paint while welding or grinding ； The bucket is left open without a lid; I’ll need it again in a while anyway. Taken individually, these things aren’t much of a concern, but when put together they create the conditions for buildup of anger that cannot be released. Once a spark appears, there’s no room left. Although most solvents have low flash points, with many being 30°C or even lower, as the ambient temperature rises, their volatility increases significantly, making it easier for them to enter that dangerous range mentioned earlier. 👉Many accidents don’t happen all at once; they result from small issues accumulating over time. To be honest, what should really be a concern on site is not the fire – people are more or less cautious about that. But when it comes to people, many places really don’t take them seriously. Those who work on site keep going even when they can’t smell anything, and they persevere even when they feel dizzy; most of them just say, “I’m used to it.” But these gases are absorbed into the body, and over time, they cause gradual damage to human health. In places where there’s a risk of fire, everyone is very careful ； You might not get to touch something on fire that many times, but when exposed to these smells every day, no one really pays any attention to them. I really hope there are fewer problems; it comes down to a few simple points: don’t skimp on ventilation – it only counts if it can remove odors ； Protection must be used correctly; ordinary masks cannot block these gases ； When the conditions are poor, don’t insist on continuing; replace the person if necessary ； Cover it once the solvent is used up, so it doesn’t keep spreading outside. None of these are difficult; it just depends on whether you do them or not. Those in this field understand after working for a while that while the risk of fire is immediate, the damage to health accumulates over time. 👉 It’s only safe if nothing goes wrong and no one gets hurt.