3 replies to this topic

[Leenanish]

Hi!

 

I work for a Perfume manufacturing company. We have been receiving glass bottles from suppliers in China and India and have noticed that many bottles have moulds growing in them. Pic attached. Suppliers refute this saying that it is bloom but it doesn't have characteristics similar bloom. We have even performed the water solubility test to rule out that it is bloom.

 

Appreciate knowledgeable feedback and any other tests to confirm this.

 

Thanks

Edited by Leenanish, 23 August 2022 - 05:26 AM.

[Evans X.]

Greetings Leenanish,

 

(A little bit of chemistry intro) Bloom is a chemical reaction, caused by residual mobile ions, such as sodium ions, that leach out of the silica sol and react with ambient moisture (SiONa + H2O → SiOH + NaOH). The formed sodium hydroxide, (NaOH) gradually dissolves the glossy outer layer of the glass and turns it hazy. So a better test, than water, that you can perform to rule it out is to soak it in HCl for about 5 minutes. Additionally, you can also swab the mould and have it grown in a petri dish to make sure it is indeed that!

One problem doesn't rule out the other, as both problems depend on the presence of moisture. So the source of this could be poor quality of the bottles or poor storage conditions that induce moisture.

 

Regards!

[Leenanish]

Greetings Leenanish,

 

(A little bit of chemistry intro) Bloom is a chemical reaction, caused by residual mobile ions, such as sodium ions, that leach out of the silica sol and react with ambient moisture (SiONa + H2O → SiOH + NaOH). The formed sodium hydroxide, (NaOH) gradually dissolves the glossy outer layer of the glass and turns it hazy. So a better test, than water, that you can perform to rule it out is to soak it in HCl for about 5 minutes. Additionally, you can also swab the mould and have it grown in a petri dish to make sure it is indeed that!

One problem doesn't rule out the other, as both problems depend on the presence of moisture. So the source of this could be poor quality of the bottles or poor storage conditions that induce moisture.

 

Regards!

Dear Evans,

 

Your reply is much appreciated. Will definitely perform the HCl test as advised. Can you let me know what percentage of HCl is to be used?

 

We did perform microscopic analysis of the filaments that were growing to check and we found typical filamentous structures as attached.

 

But we're stumped here too!

 

Appreciate your help!

[Evans X.]

Some guides for treating blooming propose a solution of HCl with a pH of approximately 4, so you could go with that. Although it is implied, I remind the use of protective measures when using acids!!!

Also, if it is bloom then they are not treating glass as they should to prevent it so it is still a problem, albeit a quality/appearance one.

Since you verified that is is moulds, then most likely it is really poor storage and warehouse conditions, allowing moisture condensation and hence mould growth.