Californias Proposition 65 and cancer causing chemicals in paint

I was recently asked about a statement on a tin of Benjamin Moore paint that reads 'WARNING: Contains a chemical known to the state of California to cause Cancer and birth defects, or other reproductive harm'

The person who asked me was particularly concerned as they have a baby due soon and most of their house is now painted in Benjamin Moore paint (some by me and some by themselves).

I fully understand the concern as I had the same thoughts when I first heard of Proposition 65, so I thought I would do some research and try to clear things up a little. I first became aware of Proposition 65 on an Amazon listing for 3M masking tape, which you can read their response too on an earlier blog post.

So what is Proposition 65? In 1986, California voters approved an initiative to address their growing concerns about exposure to toxic chemicals. That initiative became the Safe Drinking Water and Toxic Enforcement Act of 1986, better known by its original name of Proposition 65. Proposition 65 requires the State to publish a list of chemicals known to cause cancer or birth defects or other reproductive harm. This list, which must be updated at least once a year, has grown to include approximately 800 chemicals since it was first published in 1987.

The link to the current full list is in the above paragraph. But what is it in Benjamin Moore's paint that requires it to be included on their tins? It isn't a legal requirement in the UK to have the warning and is only their tins because they are imported from the U.S. - but should we still be concerned?

I have done a bit of further research into what exactly is in BM's paint that is on the list of chemicals for prop 65 and came up with one thing - Titanium dioxide. This is listed as being known to cause cancer when airborne in unbound particles of respirable size. So as far as I can tell is of no concern when used in paint.

After doing a bit of a search around I found that it is also commonly used by UK manufacturers like Dulux and Crown, so whilst Benjamin Moore bought it to our attention, it is not solely them that include it in their manufacturing process. It replaced lead compounds as the primary white paint pigment shortly after WW II. But in fact, Titanium dioxide is used in the manufacture of a lot of products that we use all the time.

It accounts for 70% of the production volume of pigments worldwide and is found in paints, plastics, papers, inks, foods, and toothpastes. It is also used in cosmetic and skin care products, and it is present in almost every sunblock, where it helps protect the skin from ultraviolet light.

Most interesting of all is that it is added to skimmed milk to make it white instead of blue!

So whilst it is concerning to see that a paint contains a cancer causing chemical, its more concerning that we are consuming it daily and applying it to our skin. However in all these cases it would seem that it is harmless because its not being inhaled.

Update after some more research:

I have been doing a bit more research on titanium dioxide and discovered a few more listed ingredients in Benjamin Moore paint.

Titanium dioxide is only listed as possibly carcinogenic in humans. in studies high concentrations of dust have been shown to cause respiratory tract cancer in rats exposed by inhalation. The same has also been seen in people working in dusty environments during titanium production, if there are insufficient dust control measures in place.

Silica -  is also on the list of carcinogenic chemicals used in paint manufacture. It is mostly obtained by mining quartz. 95% of Silica production is used in construction for Portland cement. It is also used to make glass products, micro chips, ceramics, fibre-optics and in food production.

ingested orally Silica is essentially nontoxic. However inhaling finely divided crystalline silica dust can lead to silicosis, bronchitis or cancer, as the dust becomes lodged in the lungs and continuously irritates them, reducing lung capacities.

Interestingly a study that followed subjects for 15 years found that higher levels of silica in water appeared to decrease the risk of dementia . The study found an association between an increase of 10 milligram-per-day of the intake of silica in drinking water with a decreased risk of dementia of 11%

Methylisothiazolinone - This is just a biocide and preservative. As well as paint it is used in cosmetics and some mouthwash. There has been an increase in the number of people with an allergy to it, so companies are now starting to remove it from their products.

Diatomaceous earth - consists of fossilized remains of diatoms, a type of hard-shelled Protozo. It is used as a filtration aid, mild abrasive in products including metal polishes and toothpaste, reinforcing filler in plastics and rubber, cat litter, a stabilizing component of dynamite, and a thermal insulator.

In a study of workers, those exposed to natural D.E. for over 5 years had no significant lung changes, while 40% of those exposed to the calcined form had developed pneumoconiosis. Today's common D.E. formulations are safer to use as they are predominantly made up of amorphous silica and contain little or no crystalline silica.

Propylene glycol - Is produced on a large scale and is primarily used in the production of polymers but also sees use in food processing as the E-number E1520.

The acute oral toxicity of propylene glycol is very low, and large quantities are required to cause perceptible health damage in humans. Prolonged contact is essentially non-irritating to the skin. Undiluted propylene glycol is minimally irritating to the eye, producing slight transient conjunctivitis; the eye recovers after the exposure is removed.

So from all the chemicals that I can see, only 2 require the proposition 65 label. Interestingly I noticed that Benjamin Moores Natura range doesn't carry the prop 65 label. It stills contains both Titanium dioxide and Silica - both of which are know carcinogens, so I have no idea why the label is not required. I did notice that it contains half the amount of silica, so perhaps this puts it within the legal requirement? The Titanium dioxide is still present in the same quantity as the other paints.

From what I can find nobody in America takes notice of the warning and discussions are taking place to change it, as people largely ignore it, even on product that are potentially dangerous. In California it is found on everything including houses, swimming pools and mail boxes!

Shaw paints who import Benjamin Moore into the UK may one day change the labels to their own, so the warning would not be present. They currently add a sticker to the label that covers the info required for the strict UK and EU labeling requirements and full safety data sheets are also available, which list more chemicals than the American Technical data sheets do.