-3
$\begingroup$

I have been using sodium hypochlorite bleach as a cleaning method in my house. During a two week period when I was at home I left the mop handle in the bucket with bleach in it. I did not know it was plated with chromium. I used the water once/twice on a small area of the house (3 square metres) before noticing that the mop handle had some "rust marks/browning". I tested the water and they found approximately 200 microrgams of chromium per litre in the water. It did not specify if it was chromium 3 or 6. My questions are:

  1. Should i be concerned about the amount of chromium in the water? Assuming it was oxidised to Chromium 6, would the amount of 200micrograms per litre be dangerous to health? I did not use all the water in the bucket, just enough for those 2-3 square metres.

  2. The mop handle on top also had some "rust" marks which I am guessing is from the hypochlorous acid/chlorine fumes released over the 2 week period from the bucket reacting with the handle. Any chromium 6 formed on the handle, would that have fallen off as well while i was using the handle onto my floor, adding to the chromium deposited on the floor? Or is it stuck onto the handle and does not come off?

Sorry for the specific question, any answer anyone can give will be very appreciated. x

Improve this question
$\endgroup$
1
  • 1
    $\begingroup$ Why in the name of Hades did you mop your floor with bleach? Instead of some cheap, simple, harmless, and highly effective household detergent? $\endgroup$
    – Karl
    Commented Nov 6, 2023 at 0:19

2 Answers 2

Reset to default
1
$\begingroup$

From the CDC:

EPA has an enforceable maximum contaminant level of total chromium in drinking water of 100 µg/L (100 ppb) for public water systems [EPA 1999h].

Trivalent chromium is less stringent, but because air (and certainly hypochlorite bleach) is thermodynamically capable of ocidizing Cr(III) to Cr(VI).

To reduce the chromium, you may want to consult Prasad et al.[1].

  1. Prasad, P.V.V.V., Das, C. and Golder, A.K. (2011), "Reduction of Cr(VI) to Cr(III) and removal of total chromium from wastewater using scrap iron in the form of zerovalent iron(ZVI): Batch and column studies". Can. J. Chem. Eng., 89: 1575-1582. https://doi.org/10.1002/cjce.20590
Improve this answer
$\endgroup$
0
0
$\begingroup$

In the toxicology books, Chromium(III) is said to be non-toxic. When ingested, Chromium(IV) is toxic : $1$ g Cr(VI) is lethal. $0.5$ g Cr(VI) produces stomach aches and inflammation. So $200$ micrograms is not dangerous to health.

Improve this answer
$\endgroup$
4
  • $\begingroup$ Thank you very much for the answer. Could I also ask, from the research I have read, they all deal with millimolar concentrations. I guess I am dealing with micromolar concentrations here. What form will the chromium 6 be in sodium hypochlorite? Will it be sodium chromate, sodium dichromate? Or something else? So I can look for any further information. Thank you again. $\endgroup$
    – Kain
    Commented Nov 5, 2023 at 2:59
  • $\begingroup$ Sodium hypochlorite solutions are basic, with a pH between $8$ and $14$. . So the Chromium(VI) is present as $\ce{CrO4^{2-}}$ in such a solution. $\endgroup$
    – Maurice
    Commented Nov 5, 2023 at 10:45
  • $\begingroup$ Where did you got the info that 200µg of Cr(VI) are harmless? Soluble chromates are definitely carcinogenic, not to mention that soluble chromium species are known for inducing contact allergies, often on first contact. I wouldn't be in panic here, but definitely clean the contaminated areas with gloves and a regular household detergent. $\endgroup$
    – Karl
    Commented Nov 6, 2023 at 0:15
  • $\begingroup$ The area has already been cleaned multiple times Karl. I did not specify this in my question: I mopped the area once with the water in the bucket (an area of two square metres). Once I saw that the handle had been eaten away I tested the BUCKET water (the water that remained) for the Chromium. So the 200micrograms per litre were in the bucket. It had around 3L so around 600 micrograms I know. That water was disposed of. I am hoping that the small amount of water I added to my floor contained much less Chromium. So if I used 100ml, then a much smaller amount than 200 micrograms. $\endgroup$
    – Kain
    Commented Nov 6, 2023 at 4:27

Not the answer you're looking for? Browse other questions tagged or ask your own question.