Bitrex®, the world’s bitterest substance, is the leading branded safety ingredient used in a variety of domestic and industrial applications

It was during the development of a new dental anaesthetic that researchers at Macfarlan Smith stumbled across the novel, extremely bitter tasting substance. Work continued to develop applications for the new substance and shortly after, Bitrex® – formed from the Bit (for bitter) and Rex (for king) – was born.

Two years after the original patent submission, Macfarlan Smith successfully gained approval from both the US and UK authorities to use this new chemical entity for rendering industrial alcohol unsuitable for human consumption – known as denaturing. It was this application that gave Bitrex® its generic chemical name, denatonium benzoate, and this new synthetic compound rapidly became the denaturant of choice in many countries around the world.

The first use of Bitrex® as an active aversive agent was to help solve a problem for the Danish pig farming community. Pigs had begun cannibalising each other's tails but by applying a cream containing Bitrex® to the tails, this problem soon disappeared.

New applications in child safety

In 1980, following a rise in accidental poisonings of children from household cleaning products, Bitrex® was identified as a possible remedy. Various studies were conducted which proved that Bitrex®, even at very small concentrations, was effective in reducing the volume of material swallowed by a child.

In 1982, Bitrex® was officially recognised as the world's most bitter substance by the Guinness Book of Records – in fact it is so bitter that a teaspoon full of Bitrex® would still be tasted in an Olympic sized swimming pool!

Following initial work with the Proctor & Gamble Company in the US, Macfarlan Smith launched the new Bitrex® logo to the market in 1988 with the UK retailer Tesco. Not long after, other companies such as Sainsbury's, BP and Shell began to utilise the Bitrex® brand to promote their safety stewardship programmes. Further to its use as an aversive in household cleaning products, other applications for Bitrex® followed during the 1990s, which saw its use in pesticides, such as slug baits, to prevent accidental ingestion by both children and pets. Companies such as Bayer and SC Johnson joined the group of Bitrex® partners which by then included many others such as Carrefour and Co-op.

Safety is number one

Safety is a core value of the Bitrex® brand and in developing the safety message for Bitrex®, Macfarlan Smith has established long standing partnerships with experts in the field of child safety. In the UK we have worked with both The Royal Society for the Prevention of Accidents (RoSPA) and The Child Accident Prevention Trust (CAPT), with the Green Cross in Germany, Institut Prevention Accidents Domestiques (IPAD) in France and the National Safety Council in the USA. These relationships also benefit Bitrex® customers who can align themselves with the safety organisations to promote their use of Bitrex®.

Bitrex is the third line of defence in protecting children – it's not a replacement for safe storage of dangerous household, garden and garage substances and putting hazardous materials in high or locked cupboards and ensuring dangerous products with child resistant caps are purchased whenever possible, is always vital. But Bitrex® offers an important additional safety measure.

Today Macfarlan Smith continues to educate consumers, manufacturers and retailers of the benefits of Bitrex – and when it comes to safety, it's definitely 'bitter' to be safe than sorry.