Thread: Coloring Agents

There was a situation recently where a containter of Hydrochloric Acid and one of Sulphuric Acid were poured down the sink in the belief that they were distilled water. A dozen other containers of real distilled water were in the same place and the acid tubs were simply mistaken as distilled water because no labelling or other identification was applied. No apparent damage was done but that is not to say that something drastic could not have happened as you would be aware.

Labels could be used of course but there were lame responses that labels could be worn off or washed off or any of a dozen other excuses for not using them.

I was wondering if there was an inert coloring agent that could be mixed into the acid containers to indicate that they are something other than distilled water?

So there are no coloring agents for unmarked beakers of acid?

I will just have to invent one... :-D

If you take a short whiff of HCl you'll know why you do not need coloring agents for that. And The viscosity and density of H2SO4 also is a dead giveaway for someone who's dealing with chemicals. Those who do not have the common sense not to simply pour some unknown chemicals down the sink don't have any business dealing with those substances in the first place and should be fired immediately.

Thanks for your input. It was not simply a case of pouring unknown chemicals down the sink but something that was believed to be water along with all the other containers of water in the area. No-one said it was concentrated HCl or H2SO4 so taking a whiff or testing viscosity may not have been conclusive.

And firing someone who is otherwise very good at their job my not be justifiable action against the right person if someone who should have known better didn't put appropriate labels on the containers.

So I still have to invent a coloring agent?

No need to start firing people but you or whoever is in charge do need to start enforcing standards. You cannot have people letting unlabeled chemicals lie around, or pouring unknown stuff down the drain. That's an environmental nightmare which will probably end up giving you trouble with the authorities.

Thanks Harold, I am aware of the need for procedures to be put in place but it was just one example of where something like this would be uselful. The containers that contain clear liquids in the presence of a dozen other containers of distilled water was an accident waiting to happen. The idea of coloring the acids was just one idea that came to mind.

You may be right regarding authorities but we are not generally a chemical-handling company. We manufacture electronic equipment. One of them uses a fuel cell component that we manufacture that uses HCl and H2SO4 in the process. I would have preferred to have left this component to someone who does that but you know about companies who try to save pennies and do it themselves...

Okay, I don't know about manufacturing and even less about the laws in Australia, but if I were you I'd make sure I was on the right side of the environmental regs. Those could end up costing you a lot more than the pennies you are saving.

Isn't it nice to come to a forum to ask for help and then get attacked for it?

I came into this company just recently and was told to do a particular job by my boss. There are conditions here that I think should be addressed and I am doing my best. Australia, America... they are identical as far as I have seen in my lifetime and I have spent considerable time in both.

I have as much trouble as anyone else in finding a job, let alone a reasonably good one in a company that does everything perfectly according to the laws. I have to do my job, that is as much as I can count on. So when I need to know something that would make the job better/safer/easier for me, one place to come for information is to a forum where you MIGHT get to ask people who know.

And they shoot you down...

It's not me trying to save pennies, I am just looking for safer ways of doing what someone else here didn't bother doing before I got here.

Sorry, I didn't mean to seem like I was attacking you, nor implying your company is doing anything illegal. Just trying to be helpful.

From experience, I know your real problem there is enforcement of standards. The big boss needs to lay down the law. If you cite chapter and verse of the environmental regs, that could help.

Your idea of adding a dye could help a little. If I were a chemist, I would suggest something. You would need some kind of dye that doesn't contaminate the manufacturing process, mess up a titration, or anything like that.

Wether 'tis is Ozz, US of A or Europe: for a company that has the license to use and store chemicals in large quantities there is definitely a requirement by law to properly label any chemicals that might pose a hazard to human health or the environment. I would'nt want to be the person to stand up to the authorities and explain to them what happened. I mean...in my company (some place in Europe) we had a container with mixed acid and one of the supposedly acid-proof hoses failed due to some manufacturing mishap by the company supplying these hoses. The mixed acid (50% HNO3/50% H2SO4) spilled, but was contained in the room by the protective measures also in place. Fire fighters showed up in HazMat gear and cleaned up the mess. We had a friggin' CSI-investigation to why the hell this hose ruptured

Sheesh.....so please tell the person in charge to take care of this mess i.e. proper procedures before discharging any liquids to the environment, labeling storing corrosive liquids away from other chems etc.
And what if the next time the container with the HCN get' poured down the drain??

Thank you for the comments. I know it is a serious issue and I have already voiced my objections to the management. They agree with what I have said but up until now, they say, only a very small number of people were handling the chems.

I only came here because I couldn't find any other reference to a coloring agent for chemicals that would not contaminate the process, as Harold said.

I think the best solution is to follow up with the same concerns you have presented.

Thanks again

You could just add some colored metal salts, as long as it didn't cause problems with whatever you were using the acids for.

I have worked in many chemical laboratories over the years and nobody, absolutely nobody, would ever add coloring agents to a solution simply to identify it. Unthinkable!

1) A dye is a contaminant.
2) In most labs, clear solutions must remain clear for colorimetry work.
3) It woud be an admission of incompetency.

Leaving unmarked containers of acids or any other hazardous solution lying around is already a sign of total incompetency. Someone is too inexperienced to work in a laboratory.

If I were a supervisor I would forbid such a person to set foot in my laboratory. Well, maybe not that harsh. I'm soft-hearted. We can always use a glassware technician (dish washer).
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Steve, you could say the same thing about any number of situatiouns where warning labels are applied. A warning label would be as close to incompetency as a coloring agent. Anyone, even the most competent among you, can make a bad judgement occasionally. We are only human after all. At least I am.

Chemistry isn't my main line but I don't believe I am a complete idiot. I recognized a problem and tried to address it. The world has not always been as safety-conscious as it is today and can more than likely stand a little more attention even now.

Your points were good regarding contaminents etc but I am not responsible for what my predecessors did in the lab or how much attention to detail my superiors are. I can only do what I think is right from this point on. If there is no-one in my company who can give me the answers I need, do you mind if I ask someone like you who may be more familiar with the subject?

Elijah, we are confusing two entirely separate issues. Let me first address the sample identification matter.

You tried to liken warning labels with colored solutions. Absolutely not! Labels are applied to the container only. Many similar products are distinguished by the color of their containers, such as the cylinders of compressed gases. But this is a far cry from your suggestion of coloring the product itself. That would be product adulteration, something entirely different.

We do find commercial examples. Automotive antifreeze, for example, is normally colorless. A dye, otherwise useless, is added for identification purposes. Thus we have the "green stuff", the "yellow stuff", and windshield washer fluid is dyed blue -- all to reduce the chances of a careless car owner pouring the wrong liquid into the wrong system.

Natural gas is odorless. When people sniff and say they smell gas, it is because a trace of smelly stuff is deliberately added to the supply. This is a safety measure.

Various petroleum products such as diesel fuel and gasoline are taxed at different rates depending on their use: heating, transportation, or farm use. Some of these fuels are dyed to deter dishonest people from using untaxed products in a taxable application.

But you are clearly disturbed by a separate issue. We are reading between the lines and deducing you were terminated from a job because of a laboratory mistake. You think it was unfair action. Maybe it was but -- who can tell? We are only getting half a story. Indeed, it always turns out to be much less than half.

We can offer you sympathy but this is merely the chemistry forum. We ought not to get into management practices nor legal issues. All we can really do is wish you good luck on your future.
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Originally Posted by SteveF

But you are clearly disturbed by a separate issue. We are reading between the lines and deducing you were terminated from a job because of a laboratory mistake.

I don't think he would be looking to color the acid if he had been fired.

It might not be a bad idea if they only use those two hazardous chemicals and if somebody remembers to add the dye before it is poured out into the unlabeled containers. Maybe it could be ordered that way from the supplier.

Terminated?? You may be reading words that are not there. I have just started this job. Well, I have been here 4 months now but that is relatively new. The company is primarily an electronics company, I am an electronics engineer. I did enough chemistry to get me through but it is not what I generally do.

The other day, I had to perform some operations in the lab that involved various concentrations of acid but mostly distilled water. There were a dozen containers of distilled water and two containers, identical to the others and unmarked, that contained dilute HCl and H2SO4. The concentration was about 33.5% w/v%.

Part of the process required disposal of the old distilled water to be replaced with fresh distilled water. I did that but had no idea that the other containers were not distilled water.

There is nothing more to be read into it. I wondered if there might be a way of coloring the acid mixes to distinguish them from the distilled water and so I came here. The answers have been good, coloring might contaminate the mix for its intended purpose. Fine, external labelling is the only way to go. Answer accepted. That's all I was looking for.

Where on earth you got termination is beyond me. But thanks for your input.

Here are a few comments that may be of help to you.

When you discard the DI water/unlabeled container contents (assuming these were all water to potentially dilutions of HCl and H2S04), pour them into a bucket (plastic). Check the pH and neutralize if necessary before emptying the bucket.

Your nose should tell you if it is HCl. Your nose can detect the acidic smell down to around 2Molar (12Molar or 37% is concentrated). I do not recommend sniffing the source, but when taking the cap off, the fumes could be detected by the nose a couple of feet away. The more concentrated the acid, the stronger or more pungent the fumes.

Dilute H2SO4 would be difficult to distinguish from water. The more concentrated it is, the more difference you would notice. The more concentrated it is, the more heat will be generated when adding it to water and the more is will spit, pop and splash. Concentrated H2SO4 is thick and heavy and would have a consistency similar to pancake syrup.

Labeling, as you know, is the Best Laboratory Practice.

Another possibility is to use colored caps for your reagents. I would use the same color as the stock acid bottles. Blue for HCl and its dilutions, Yellow for Sulfuric acid and its dilutions, no color for water.

Thanks Chemnut

The "distilled water" doesn't have an odour of its own, however, while pouring it down the sink, with water running, there IS a distinct chlorine smell and the water becomes slightly foamy as though there is soap in it. Not much but it is there. The other containers that definitely were acid caused a lot of foam.

I am sorry for offending anyone here but as it turns out, I am the only one who can work with this stuff and I have recommended to management that we leave it to some other company who IS qualified, or employ someone with the necessary expertise. It is too small a part of the process to employ someone full time and the rest of the process has nothing to do with chemical handling. I think the best I can do is get proper protective gear (which they dont have btw) and enforce the use of that gear, plus effective labelling.

All work in that area has been stopped pending the outcome of an investigation into the safety aspects. Thank you all for your help. Greatly appreciated. :-D