Some Ink pH Levels Available in Japan but only a Selected 222 Few

[Algester]

I'm also curious as to why most Blue Black inks (I think the lamy Blue Black is a typo?) seem to be more on the acid side of the scale

[jmccarty3]

I'm also curious as to why most Blue Black inks (I think the lamy Blue Black is a typo?) seem to be more on the acid side of the scale

 

The correlation would appear to be at least partly between iron gall and acidity, more so than color and acidity.

[Algester]

 

The correlation would appear to be at least partly between iron gall and acidity, more so than color and acidity.

And yet Bleu Myosotis isnt an Iron-gall ink but its still in the acid side of the scale

 

I would believe if it was Platinum, R&K, KWZI which are in the list

[Olya]

 

The correlation would appear to be at least partly between iron gall and acidity, more so than color and acidity.

 

I don't think so, as Algester points out, non-ig inks are just as acidic and I think Lamy Blue Black isn't an IG anymore..

[Algester]

I don't think so, as Algester points out, non-ig inks are just as acidic and I think Lamy Blue Black isn't an IG anymore..

heck the fact if it's true that Lamy's Blue Black is in the 7.1 pH scale would make it the oddest of the bunch of blue-blacks

[lgsoltek]

Very interesting information, thank you for discovering this and doing the translation! Although I admit knowing the pH level of an ink won't affect my purchase decision in anyway...

[PithyProlix]

So, assuming these numbers are correct, wouldn't the Platinum iron galls, for instance, be considered highly corrosive? 

 

Per this page (there are many others), "A solution is considered hazardous when aqueous solutions have a pH level of less than or equal to 2 or greater than or equal to 12.5 on pH levels."

• Hydrochloric acid, 1.1 pH: "immediately dissolves skin tissue when in contact"
• Nitric acid, 1.2 pH: "can cause severe burns, dermatitis, ulcerations and yellow staining when in contact with the skin"

My chemistry knowledge is, well, pretty terrible. Am I missing something? If not, the reported ink pH levels seem very suspect.

[A Smug Dill]

15 minutes ago, PithyProlix said:

… wouldn't the Platinum iron galls, for instance, be considered highly corrosive? 

 

Corrosive to what exactly?

 

17 minutes ago, PithyProlix said:

"A solution is considered hazardous when aqueous solutions have a pH level of less than or equal to 2 or greater than or equal to 12.5 on pH levels."

 

I wouldn't recommend soaking your hand in it, any more than I'd recommend rubbing your hand hard against a rough physical surface, as that is also apt to damage your skin tissue. Household bleach and ammonia solutions are also hazardous (even if you don't mix them!), and can damage your skin on contact. Even very dilute solutions of such can damage some pen body finishes and/or metal trim on prolonged contact; I learnt that the hard way, first-hand.

 

Are you tacitly asking why the particular inks aren't subject to local/import regulations requiring hazardous products to be prominently labelled as such on their packaging? Or why (some) postal services still allow those inks to be sent through in the post? Some postal services categorically refuse carriage of liquids, or at least those without being accompanied by (Material) Safety Data Sheets attesting that they are safe. There is no categorical prohibition or restriction on ink being imported into Australia; but you are not allowed by postal regulations to put hazardous and/or corrosive material in articles carried by Australia Post. However, it's primarily up to the sender to make complete, accurate and honest declarations as to whether there is such in an article's content, and (better still) observe the rules in the first place and refrain from sending such in the post, instead of trying it on for size and risk getting it detected and rejected/confiscated/dumped (with or without fines).

[Ergative]

1 hour ago, PithyProlix said:

So, assuming these numbers are correct, wouldn't the Platinum iron galls, for instance, be considered highly corrosive? 

 

Per this page (there are many others), "A solution is considered hazardous when aqueous solutions have a pH level of less than or equal to 2 or greater than or equal to 12.5 on pH levels."

• Hydrochloric acid, 1.1 pH: "immediately dissolves skin tissue when in contact"
• Nitric acid, 1.2 pH: "can cause severe burns, dermatitis, ulcerations and yellow staining when in contact with the skin"

My chemistry knowledge is, well, pretty terrible. Am I missing something? If not, the reported ink pH levels seem very suspect.

 

Yes, that looked odd to me too.  If Classic Lavender Black truly has a pH of 1.1, then it should immediately dissolve skin tissue when in contact. Has anyone here gotten any Platinum Classic Lavender Black on their hands?

 

When we worry about ink corrosiveness, it's always in the context of 'will it hurt my pen? Will it damage my feed? Will it eat my nib?' It's never 'will it dissolve my skin'? Surely, in all of our ink reviews, in all of our inky hands, in all of our millions of pen-fills, we would have noticed that some inks hurt when they touch skin. 

 

I think I'm with you, PithyProlix. I don't think I believe those pH numbers.

 

This sounds, actually, like a problem for our resident chemist with equipment, @InesF--or, indeed, any other resident chemists--to test.

[PithyProlix]

36 minutes ago, A Smug Dill said:

Are you tacitly asking why the particular inks aren't subject to local/import regulations requiring hazardous products to be prominently labelled as such on their packaging? Or why (some) postal services still allow those inks to be sent through in the post?

 

I am asking if the reported ink pH values are valid. I understand that strong acids are not necessarily corrosive or caustic, given their reactivity with whatever it is they contact, but don't they have a strong tendency to be? pH of 1.1 (Platinum Classic Lavender Black), which is the same pH at which a solution of hydrochloric acid immediately dissolves skin, is a pretty extreme value, isn't it?

[A Smug Dill]

16 minutes ago, PithyProlix said:

I am asking if the reported ink pH values are valid.

 

I'd hazard a guess that the pH values were measured with equipment, and reported in the table/article as-is. Were they all wrong, in that the equipment wasn't properly calibrated with standard/reference solutions (as often as required)? Or was there contamination between tests for different inks, because of sloppy procedure? I don't know for sure, I wasn't there; but I seriously doubt it.

 

21 minutes ago, PithyProlix said:

I understand that strong acids are not necessarily corrosive or caustic, given their reactivity with whatever it is they contact, but don't they have a strong tendency to be?

 

I don't think it means a single drop on your hand is going to cause your skin to fizzle, or start to ‘burn’ a hole through your flesh while you scream in pain, immediately as if it was a sci-fi/horror movie.

 

24 minutes ago, PithyProlix said:

pH of 1.1 (Platinum Classic Lavender Black), which is the same pH at which a solution of hydrochloric acid immediately dissolves skin, is a pretty extreme value, isn't it?

 

I actually don't doubt that some cells in the epidermis will die from their walls being dissolved and/or compromised by the acid on contact, which then results in ‘solution’ being less acidic than before with the addition of each cell.

 

 

[InesF]

On 1/6/2022 at 7:32 AM, PithyProlix said:

Hydrochloric acid, 1.1 pH: "immediately dissolves skin tissue when in contact"

Please consider the pH-value of 1.0 in our stomach caused by presence of HCl. Nevertheless, I would not drink 1M HCl (because of dissolving the teeth surface).

 

I'm working in the chemical lab since roughly 42 years now, had several incidents with all those strong acids and bases and would not be afraid of a hydrochloric acid with pH 1 - because this is not critical. It starts to become more serious if you spill concentrated hydrochloric or sulfuric or nitric acid over your skin. But even then, except for the sulfuric acid, you may have 20-30 seconds time to rinse it off with tap water before any honest damage occurs. Remember the skin oils - those prevent the direct contact to the sensitive tissue!

Much more honest are strong bases! Why? Because they hydrolyze the skin oils (making soap) and come into contact with the tissue in due time. However, this effect does not start below pH 10 and starts having significant speed (= reduced reaction time) at pH 13-14.

All fountain pen inks are far, far away from the 'danger zone'!

[PithyProlix]

3 hours ago, InesF said:

Please consider the pH-value of 1.0 in our stomach caused by presence of HCl. Nevertheless, I would not drink 1M HCl (because of dissolving the teeth surface).

 

I'm working in the chemical lab since roughly 42 years now, had several incidents with all those strong acids and bases and would not be afraid of a hydrochloric acid with pH 1 - because this is not critical. It starts to become more serious if you spill concentrated hydrochloric or sulfuric or nitric acid over your skin. But even then, except for the sulfuric acid, you may have 20-30 seconds time to rinse it off with tap water before any honest damage occurs. Remember the skin oils - those prevent the direct contact to the sensitive tissue!

Much more honest are strong bases! Why? Because they hydrolyze the skin oils (making soap) and come into contact with the tissue in due time. However, this effect does not start below pH 10 and starts having significant speed (= reduced reaction time) at pH 13-14.

All fountain pen inks are far, far away from the 'danger zone'!

 

Thanks for the reply.

 

But does a pH of 1.1 for an ink sound like a reasonable value? My concern wasn't so much ink contacting the skin - that was just to show the potential of an acid with a pH that low. My concern is much more that such a strong acid is in continuous contact with the pen, then paper.

[Noihvo]

[InesF]

20 hours ago, PithyProlix said:

My concern is much more that such a strong acid is in continuous contact with the pen, then paper.

That's the reason why those cheap iron dip pens start rusting after some weeks in use while the steel and gold nibs of fountain pens do not.

Paper will be hydrolyzed over the years - a well known damage pattern caused by iron gall inks of old. Those inks could have had pH values below 1.

And again, as long as you do not take a bath in pH 1 HCl nor drink it nor spill it in your eyes, very little will happen to your skin.