Problems with Silica Gel Cat Litter
How safe are your cats with silica gel cat litter?
Silica gel cat litter is often touted as harmless to humans and animals alike. However, some people use crushed silica gel to kill bed bugs and cockroaches!
What exactly is Silica Gel Crystal Cat Litter?
Silica crystals are filled with millions of micro pores that adsorb moisture. Silicon dioxide (the type of sand found in quartz), when mixed with oxygen and water, turns into Silica Gel Crystals. The crystals are super adsorbent and suck the moisture out of kitty poo. No wonder it is so popular amongst cat owners.
What we see as silica cat litter is usually a synthetic form of silicon dioxide derived from sodium silicate. It is a fairly recent innovation and was patented by Professor Walter A. Patrick in 1918.
ADsorb vs ABsorb
A substance is adsorbent when other substances (dissolved solid/liquid/gas) stick to its surface (or adhere to it) at a molecular level.
Other than silica gel, activated charcoal is a good example.
Even though silica gel is extremely porous at a microscopic level, the liquid (which includes dissolved solids) part of cat excrement just forms a film on the surface of the pores instead of being sucked inside of them (and sort of becoming a part of them).
A substance is absorbent when other substances (liquids) are dissolved in it or can permeate it.
Example of dissolve: ink being dissolved in water.
Example of permeate: ink being soaked up by blotting paper.
Clumping cat litter (with or without sodium bentonite) will absorb the fluid from cat excrement and form a solid clump of varying degrees of hardness.
Sodium Bentonite is not the only cat litter culprit. Clay is harmful if inhaled in dust form. Apart from that, in clay based clump cat litter, silicon constitutes most of the dust particles. That is not a healthy situation for either the human members of the household or the one with the paws using the litter.
The possible carcinogenic (causing cancer) property of silica, and the disease Silicosis should not be taken lightly, either (although silicosis is suspected to occur from dust that comes of natural silica).
The blue colour often found in silica gel cat litters that indicates that the litter is fresh (it turns pink upon absorption of moisture) is due to the presence of Cobalt Chloride. This, again, is ‘possibly carcinogenic’ to humans and definitely hazardous to aquatic life and to the environment in general (use of Cobalt Chloride has been restricted in Europe since 2000 after being reclassified as a carcinogen).
Cobalt Chloride free Silica Gel is being made available in the market for precisely that reason though not as cat litter.
Related: Get the best of both worlds with Organic Flushable Cat Litter (updated Feb 2017)
Is silica gel cat litter safe for cats and humans?
Excerpts from THREE different sources ought to illustrate exactly how harmless it really is as cat litter.
We move from the least to the most alarming of the three instances.
1. Comment in a forum from a crystal cat litter user:
We have been using “crystal” cat litter that is a silica gel for several months. It is far and away the best litter we’ve tried in terms of odor control and ease of use.
However there is a tremendous amount of dust emanating from the stuff. It is so heavy, I fill the box by taking it outside, holding the bag several feet above the box, and pouring slowly so the dust blows off in the breeze. I hold my breath too. If by chance I breathe it, intense coughing is the result.
I’ve also noticed a few times, that when the box is fresh, the cat will leave the box and wheeze a few times
2. Excerpt from a case study on silica in cat litter and its effect on cats:
Inhaled silica dust has been implicated as a cause of lung cancer and other respiratory diseases in humans and several animal species.
Electron microscopy and x-ray spectroscopy were used to identify and characterize dust particles from seven brands of commercially available clay cat litters and to identify, characterize and quantify particles in the lung wash fluid of six cats with and six cats without signs of respiratory disease.
Dust particles from clay cat litter have an identifiable appearance and elemental ratio (primarily aluminum and silica) and the same pattern was observed in particles obtained from lung wash fluid. Significantly more silica particles were obtained from cats with than without respiratory disease.
This suggests an association between presence of silica particles and respiratory disease, but it is unknown whether silica dust particles contribute to respiratory disease or accumulate because of interference with normal lung ciliary function.
3. Sarcoidosis and silica gel cat litter – you’ll likely find the connection as shocking as we did.
What on earth is Sarcoidosis?
Sarcoidosis (SAR-KOI-DOSIS) is a disease caused when the body’s immune system overreacts. While it is not yet known exactly what causes the overreaction
While it is not yet known exactly what causes the overreaction there is reason to believe that it may be triggered by a response to some specific substance inhaled from the air (like dust from silica cat litter, perhaps?).
The most visible symptom is the formation of granulomas which appear as unnatural lumps or nodules. These are caused by inflamed cells clumping together. Most frequently affected organs are the lungs and the lymph nodes but other organs may be affected as well.
Good news is, Sarcoidosis has been known to go away on its own and with supportive medication patients can live a close to normal life.
Unfortunately, there is no known cure for Sarcoidosis. If it takes an aggressive turn, the granulomas can cause irreversible damage to the affected organs.
There are about 200,000 individuals affected by Sarcoidosis in the US.
- Unexplained shortness of breath
- Swelling and pain at joints and extremities
- Unnatural or missed heart beats (arrhythmias)
- Hearing loss
- Blurry vision and symptoms like conjunctivitis
- Tender bumps and patches on the skin
- Psychiatric disorders like dementia and psychosis or even general depression
Here is a video to round off this part of the discussion. We suggest you skip it for now and scroll down to read what is arguably more important for you if you’ve been using silica gel cat litter.
(Silica Gel) ‘Cat litter is a possible trigger for sarcoidosis’
Excerpts from study published in the European Respiratory Journal, December 31, 2011
Inorganic agents, including silica, have been reported to initiate inflammation and granulomatous reactions… We propose that silica, the major component of cat litter, might be such an agent.
We report a case of biopsy-proven sarcoidosis with birefringent material, mainly silica, within the lung biopsy specimen. The patient had no relevant occupational history, but had cats and was extensively exposed to silica-containing cat litter.
Initially, the patient improved after starting immunosuppressive drugs and terminating contact with litter. However, she deteriorated twice after autoprovocation (re-exposure) to cat litter. After changing the silica-containing cat litter for litter without silica, her clinical condition improved substantially.
Obviously, she appeared to be “hypersensitive” not to the cats but to the cat litter.
Although crystalline silica exposure has been known to be associated with sarcoidosis, the present case provides evidence of an unexpected association between the substantial exposure to silica-containing cat litter and sarcoidosis or a “sarcoid-like” granulomatous reaction.
Obviously, this is important, as many people have cats with litter boxes.
Therefore, it was recommended not to get rid of the cats but rather choose appropriate cat litter, without silica.
This case stresses: “if you are not aware of it, you will not recognise it!”
You should probably read the entire article.
If that doesn’t convince you to reconsider your decision to use silica gel cat litter, we don’t know what will.
There is a growing resentment among patients of Sarcoidosis that since the number of people affected is relatively low, there hasn’t been much research on determining a cure.
The theory (which makes sense, actually) is that Big Pharma funds most such research works and it wouldn’t make sense to fund a research that might serve to bring relief to a small number of people. The investment simply wouldn’t be worth it.
Be that as it may, one cannot help but wonder what might turn up if more studies like the one cited above were conducted.
'Cat litter is a possible trigger for sarcoidosis' ~European Respiratory Journal Click To Tweet
Is any silica gel cat litter safe?
We’re not sure, but in all fairness, we should mention the Ultra Pet brand which claims to use a vegetable dye instead of cobalt chloride and says the following about dust:
There may be a small amount of powder on the product, but generally the product is over 99% dust free. This is the result of pearls rubbing together during transport. Once you have opened the bag you shouldn’t have any problems with dust—if you do please call us.
The brand also claims to be relatively environment-friendly:
…70 percent less landfill contribution than clay litter.
However, we would still recommend organic alternatives because they get the job done while being 100 percent eco-friendly.