Does your Valspar paint smell of cat urine?

The growth of bacteria in water-based paint in paints has become a problem for manufacturers following removal of certain chemical biocides that are no longer permitted, presumably for safety reasons – many chemicals that are harmful to bacteria are also harmful to humans. The unpleasant smell reported is I understand not present when the paint is applied but due to growth of certain bacteria present in/on the walls, resulting in the production of hydrogen sulphide and ammonia. There is unlikely to be a quick test that manufacturers can use to test their paints. I do have some sympathy because of the challenges that manufacturers are facing trying to provide us with safer products.

As retailer, B&Q should be handling all complaints promptly and not a single case should have been referred to Valspar. I do not know what Valspar have done to tackle the problem but there seems to be very few cases compared with when there were numerous reports in the press.

This is reminiscent of washing machines and dryers being referred to Whirlpool, instead of the retailer taking responsibility under the Consumer Rights Act. The consumer should not suffer because of a manufacturer’s problem, with the retailer as the responsible party contractually.

Can Which? tell us what action they have taken to help consumers obtain appropriate redress from B&Q.

There must be some factor in the Valspar paint that promotes or accelerates the reaction that releases the smell. I have never experienced such an effect with emulsion paint made by Crown or Dulux or own label paint from Homebase or Wilko.

Is current B&Q Valspar paint still a problem?

As you say, John, other water based paints appear to perform well without this problem; they are common for domestic, commercial and industrial use. Valspar are, I believe, owned by a large American group and should have the technology to produce acceptable paints. Are the products sold by B&Q different from their standard products?

I wonder if B&Q have had the paint problem investigated to determine its possible cause. I don’t know whether, for example, the Paint Research Association have the expertise and ability to help.

John – The problem is not a simple reaction but growth of bacteria or other microorganisms. For example, sulphate-reducing bacteria produce hydrogen sulphide. That would fit in with the smell not being noticed after painting but weeks or months later. Previous wall treatments such as size and wallpaper paste may promote bacterial growth by providing nutrients for the bugs.

The reason we are seeing problems with Valspar paint was the removal of a biocide (preservative) to comply with EU law, as explained in the introduction. I have some mouldy paint in my garage and within the last week I was speaking to a friend who has had the same problem with Dulux paint. I expect that the industry is devoting effort trying to find biocides that are sufficiently effective but reasonably safe for use, particularly by those in the trade who use them regularly.

There is useful advice in the introduction: “This would allow the buyer to seek a full refund and claim consequential loss, such as a decorator’s labour charge if the paint has been applied to a wall.” B&Q might like to draw a line under the problem but if there are still cases, it must comply with the law.

Whilst this might not be a simple problem it does not seem to be a general problem with water-based paints, that are widely used. My son’s house was totally repainted recently using Farrow and Ball paints – water based – with no smell issues.

Is there some particular circumstance that causes the bacterial problem that is peculiar to those who have experienced the smell? The underlying surface, lack of preparation, or is B&Q Valspar a particular formulation that is defective?

No edit button still. I was going to add it is reminiscent of smelly kettle water, another unresolved problem.

Although the cat smell seems to be a Valspar speciality. From what I have read, the problem does not seem to appear soon after painting.

Bacteria and other organisms require a range of nutrients to grow, just as we do to remain healthy, plus moisture. The purpose of including biocides is to prevent significant growth of bugs if these nutrients are available. Different manufacturers may choose different biocides and amounts, within the limits of what is permitted. If I was preparing a wall I would wash it very thoroughly to get rid of paste and use a sealer on the surface – a measure that is recommended for dealing with smell problems.

If you can find current SDS for paints it should be possible to see the differences in choice of biocides for brands, though information online. is not always up to date.

We have Valspar on the walls in one room, colour made to order, now over 2 years old, and I have just given it a close sniff test – no smell whatsoever.

After reading the comments here, I have been half-expecting a smell to develop but so far so good.

To add to this, microbial contamination of paints is well established and the move from solvent to water-based paints has created additional problems. Here is a brief article that looks just at the problem before the paint is even used: https://www.luminultra.com/smelly-paint-why-we-must-keep-microbes-out-of-chemical-products/

Alfa – I asked around after the Valspar problem was in the news and although I found people who had used the paint, none had experienced a problem.

The moisture content of the walls might be a factor. Some homes are quite humid thanks to high occupancy, uninsulated walls, poor ventilation and gas cooking. These factors can promote mould growth. Moisture is also needed for bugs to grow in/on paint that has been applied.