A meeting of the Yorkshire Branch of the Institution of Occupational Safety and Health (IOSH) was told that those doing the assessment should also obtain information on the "physicochemical properties".
Dr Richard Goff, Risk Assessor and Process Engineer at the Health and Safety Laboratory, said this information should include flammable limits, flashpoints, boiling points and minimum ignition energies.
He said that organisations should always look to use less hazardous substances where possible.
When this is not possible, they should control the risks in a number of ways, including by reducing the quantity of the substances present, minimising the likelihood of a release and avoiding sources of ignition.
Health and safety professionals and senior business leaders attended the event, held at the John Smith's Stadium in Huddersfield on Friday 3 March. It was held by the IOSH branch to inform businesses in the area of the Dangerous Substances and Explosive Atmosphere Regulations (DSEAR).
Paul Gillespie, Vice-Chair of the IOSH Branch, said: "It is obvious that more and more safety officers, advisers, managers, as well as environmental officers and consultants are being asked for advice on dangerous substances and explosive atmospheres in the workplace.
"Examples include welding and burning operations in garages and workshops and fumes that are produced in hair salons and nail bars. There are also the storage of petrol, diesel and gas oil in garages, grounds maintenance workshops and highways departments.
"As a branch, we often get asked questions by our members about the regulations. This event was an opportunity to ensure businesses in the area are fully briefed, so they can ensure they are minimising the risks to their staff."
The event also saw presentations from David Craig, Associated Director for Risk and Safety at E&I Amec Foster Wheeler, and Brian Humm, Former Head of the Petroleum Group at London Fire Brigade.