Hundreds of deaf pupils could benefit from a project that is building a suite of new sign language symbols for scientific terms and concepts. Edinburgh University's School of Education has developed glossaries for British Sign Language (BSL) covering biology, physics and chemistry.

The school's Scottish Sensory Centre had already produced more than 80 individual signs for mathematicss in a pilot project.

So far, more than 250 words or phrases have been created in response to growing demand from deaf pupils and teachers for a wider scientific vocabulary in the commonly used language.

They include biological terms such as evolution, hybrid and photosynthesis, concepts from physics such as gravity, joule and magnetic field and from chemistry: acid, alkali, reaction and periodic table. These are designed to be of use to deaf pupils, parents and teachers of deaf children.

It is often difficult for deaf children to grasp scientific concepts, and dictionaries can be unhelpful as the reading skills of deaf children are often weak.

Rather than traditional finger-spelling of the words for unfamiliar terms, the intention was to provide teachers and learners with more immediate signs which also aid understanding, with gestures which make intuitive sense.

Rachel O'Neill, of the university's School of Education, an expert in BSL and in the transition from education to work for deaf learners, was one of the prime movers behind the project.

She says the language is in a stage of rapid expansion. "A lot of languages have times when they suddenly need to increase their vocabulary. Sign language hasn't historically had a huge amount of science vocabulary," she explains. "Until deaf people could go to university they weren't really studying science."

That changed in the early 1990s with the arrival of the disabled student's allowance. "Since then deaf people who use sign language have graduated and got jobs in a whole range of areas."

The signs could be a breakthrough which will boost the performance of deaf pupils studying science, according to O'Neill, herself a hearing teacher of deaf pupils and students.

The new glossary was developed with the help of 10 deaf workers, including both teachers and those working with deaf pupils. Deaf scientists from the University of Durham contributed, as did John Denerley, the deaf manager of Galloway Wildlife Park, who O'Neill says was able to bring his expertise to bear on biology vocabulary.

Much of the initial work on the mathematics glossary was carried out by the late Dr Mary Brennan, a highly respected deaf education specialist who died in 2005.

The glossary means that simple words and concepts can be communicated with a single hand gesture, rather than as at present having to be spelled out letter by letter.

Apart from this method, lip shape has been one of the only other methods available for deaf learners to communicate about science, but this latter method is often unsatisfactory, O'Neill adds.

Teachers have also used shortcuts, with a capital letter T standing in for transpiration, for example. But if the capital letter R means reproduction, O'Neill points out, how do you sign the word respiration? In any case, such signing doesn't help deaf learners understand or remember scientific concepts.

In Scotland, children can take exams in BSL, with the questions signed to them and the answers signed in return. This is not the case in England and Wales although pupils can have papers signed to them, O'Neill points out. "So it is particularly important in Scotland that deaf pupils can have curriculum signs, so they can use them accurately in exam situations."

While designed for use in Scotland and the UK, the signs could be taken up further afield. New Zealand and Australia have a very similar sign language to BSL and will be able to access the explanations, the team hopes.

It isn't unusual for languages to have periods of expansion, O'Neill says. Both Welsh and Gaelic have had to expand their vocabulary for the modern age. But one of the intriguing aspects is that you can't make people use the new terms.

"We can't be sure these signs will be adopted. People may reject them: individual signers make their own decisions about which terminology to use. But the exceptional quality of this project means there is every chance these new signs will be widely used."

The signs are being promoted by a website, funded by the Scottish government, which has clear on-line video clips of the terms and definitions in BSL.

The sign for "air resistance" for instance, is demonstrated by a man apparently blowing hard on his left fist, while fanning it with his right. The learners involved in developing the signs have been filmed demonstrating them for the video clips.

The project still has important limitations. The 80 maths signs make up just over a quarter of the 300 the team would like to define.

Similarly, full definitions, written to help learners understand the concepts being signed, are not available for all 250 scientific terms.

Meanwhile, more signs are needed in all subjects to enable the scheme to cover as far as Standard Grade science comprehensively. Funding is being sought from science trusts and foundations to enable the next phase of the project.

"We want to keep going until we can get it to do everything we need it to do,"

says O'Neill.