Risk Assessments

Risk assessments play a crucial role in chemistry, providing a framework to identify potential hazards and manage any risks to ensure work can be carried out safely. All practical work being undertaken in teaching labs (and the wider department) needs to have been appropriately risk assessed prior to any work being undertaken.

Across the department a standard risk assessment template has been introduced, which allows the systematic identification of potential hazards, assessment of risks, and mitigation measures to be identified.

The creation of risk assessments is often controlled through the use of a document management system, which allows for the creation, review, approval and archiving of these forms. For all undergraduate students, each individual risk assessment must be reviewed and approved by a member of staff who has the appropriate expertise prior to any experimental work taking place. Preparing suitable risk assessments is a skilled task, and it is likely that you may be asked to review aspects of your assessments, particularly when you are new to the process.

Substance risk assessment

The following template can be used where substances are being handled, but no chemistry (ie reacting of materials) is being performed. This form would be appropriate where spectroscopic measurements were being undertaken on a material. Note that a separate specific risk assessment should be in place for the techniques being used, as this assessment only considers the hazards of an individual substance or substances in isolation from each other.

General risk assessment

A general risk assessment template is also provided by Health and Safety. This template may be useful for risk assessing activities, but this is not designed to cover COSHH or reaction risk assessment requirements.

Locating information for a risk assessment

In order to complete a risk assessment, information will need to be obtained from a variety of sources which covers the various aspects examined in the risk asssessment.

Chemical hazards

Information on chemical hazards for commercially available starting materials and be found in Safety Data Sheets (SDS) produced by the manufacturer. The structure of Safety Data Sheets is regulated, leading to a consistent format, which simplifies the process of locating information. Chemical supplier websites are usually the starting point to locate safety data sheets.

For solvents used in the department, a collated list can be found below with links to the relevant safety data sheets.

Finding chemical hazard information can be problematic, as reactions are often performed to make materials which are not commercially available, and no safety data sheet may have been produced by a manufacturer. Advice should be sought from your supervisor as to how best to assess the potential hazards from these chemicals, which might include strategies such as comparing with similar materials where data is available, and considering likely physical properties of the material.

Reaction hazards

There are a number of aspects to consider in identifying reaction hazards, and you should seek advice from project supervisors and other experienced chemists when undertaking a risk assessment. Some areas to consider would include:

• Identifying all products formed in a reaction, along with any by or side products (and these would need adding ti your chemical hazards section)

• Considering any materials which may result in hazardous reactions (see the stability and reactivity section of safety data sheets)

• Consideration of the thermodynamics and kinetics of a reaction. Is it likely to be exo or endothermic? Will any gases be evolved? Are there any initiation steps involved?

• The scale on which the reaction is being performed

• Has this work been undertaken before, and were any additional hazards identified?

• What reaction techniques are planned to be used, and are these appropriate?

Standard methods and techniques

Across the chemical industries (and in many other fields as well), standard operating procedures are usually developed within an organisation or company, as being the most appropriate way to carry out a given procedure. These procedures are developed as the most-appropriate route for carrying out a particular manipulation, with safety being a major consideration in the procedure design. Procedures will vary between different places and individual labs, having been tailored to suit the specifics of the working environment. Procedures are also periodically updated, particularly where learning can be gained from potential or actual adverse incidents which may have occurred (both internally or externally).

When preparing reactions, it should be usual practice to carefully follow these standard procedures, unless there is good reason to deviate from them for a particular case. Where it is planned to deviate from a procedure, this should be clearly documented, explaining how the procedure is being modified, and the rationale behind this.

In the preparation of risk assessments, clear reference should be made to the procedures being followed, such as the inclusion of links to the SOP, and taking the time to see if there are any updates to the documented procedure.

Where a technique is being employed which does not have a documented standard procedure, additional preparation will need to be undertaken to consider the technique being employed, and how this should be carried out. Where an occasional technique is being more routinely employed, a full standard procedure should be developed.

Quenching and waste disposal

Reaction quenches and waste disposal are areas of risk assessments which are commonly neglected, but are steps with potentially significant hazards. Consideration should be made for how to safely quench a reaction, and how chemicals will be isolated or removed from a reaction. This is particularly important where higher hazard chemicals have been identified (both on reactivity and health grounds), and where these compounds will ultimately be isolated. Some compounds will require treatment before they can safely be disposed of, which might occur in reaction quench or workup steps, or may need to be specific treatment prior to disposal of the chemicals.

Procedure and Mitigations

Once a planned reaction has been considered and any hazards identified, then consideration should be given to how the safety of the proposed reaction could be improved. This might see substitution of chemicals with less hazardous alternatives (for instance, solvents may be able to be substituted, or a safer analogue might be targeted), or an alternative route to prepare the material might be sought.

It is vital to consider the hierarchy of controls, where the following should be considered in order:

1. Elimination (is this work nescessary, or is there an alternative approach?)

2. Substitution (can a less hazardous reaction be employed or can higher hazard chemicals be substituted for safer alternatives?)

3. Engineering controls (how can humans be isolated from the risks)

4. Administrative controls (are the workers appropriately trained / familiar with the procedures?

5. Personal protective equipment (final line of defense - what PPE could protect the worker)

Where a reaction is considered to have appropriate hazards, planning should then focus on how to manage the identified hazards, so that the risk of the reaction can be reduced and controlled appropriately. There are many aspects to this including:

• Consideration of potential exotherms, and how these steps might be performed (reaction cooling, slow additions etc)

• Management of gas evolution

• Reaction primary and secondary containment

Planning for what to do if things do go wrong (fire, spills, first aid etc) should be carried out. It is important to know how to deal with things going wrong in advance, for instance if a reaction is spilled, knowing how to clear it up has already been planned for.

Project Work

Risk assessment creation and management is handled in Teaching Labs via Google Sheets and Docs. A Risk assessment creation tool will be provided for each individual project allowing you to create risk assessments from a blank template or a copy of a pre-existing one.Specific training will be provided on this when you are required to create risk assesmsents for your work in the Lab. However,  instructions on file creation for staff and students are also provided below along with an instrucitonal video. Once a risk assessment has been signed off by a supervisor a PDF summary sheet will be generated automatically, these will be printed by the Technical Staff and will be available to collect before you begin working.