Our ref: HSR/1/13

Head Office Circular: NP/183/22

26th August 2022

To: The Secretary




Dear Colleague,




Your 2022 Annual General Meeting adopted the following resolution:


This Conference recognises the importance of colour vision to the safe operation of our industry however the use of a single test may well be detrimental to some of our members.


On page 1 of Identification of a robust colour vision testing protocol for the rail industry (T924), published in April 2014, by RSSB it is noted that:


‘Research in other industries has shown that some individuals with a mild to moderate degree of red-green colour vision deficiency (who would fail this [Ishihara] test) are able to carry out selected colour-critical tasks with the same degree of safety as individuals with normal colour vision (normal trichromats).’


RSSB published a further paper Colour vision testing (S352) in November 2020 investigating a number of factors relating to colour vision requirements of railway workers.


On page 8, it is noted that Health and Safety Executive guidance specifically advises three tests for occupational colour vision assessments: Ishihara test, City University test and Lantern test. The guidance further states:


‘There should be consultation with an occupational health provider about the choice of test and consultation with employees over implementation.’


This report concludes on page 25, that use of the Ishihara test is:


‘Most likely excluding some applicants or existing employees from driving trains when they are capable of doing so safely.’


The report recommends that change is made to colour vision assessment methods and standards, while accepting that individuals who are capable are being excluded.


London Underground are noted as having made adjustments to take into account colour vision yet mainline railways are still only using the outdated Ishihara test. It must also be noted that other employers where colour vision is necessary such as the Police are already using the more modern testing methods.


There could well be implications under the equalities act in terms of protected characteristics, it could be argued people dispatching trains using colour vision is ‘normal’ and ‘day-to-day’ in that environment. It is, therefore, likely that colour vision deficiency would be regarded as a disability in the context of railway safety critical duties.


Section 11 of the Equality Act 2010 identifies sex as a protected characteristic. The provision states that the law references a man or a woman. It is imperative to note that males experience colour vision deficiency to a significantly higher degree than females. 8% of males of Northern European descent have some degree of red-green colour vision deficiency versus 0.5% of females.


The industry’s insistence on exclusive use of the Ishihara Plates Test, shown to be of little use in determining the severity of one’s colour vision, could potentially be in breach of the equalities act. This failure is further compounded by the RSSB’s recognition of the hampering nature of the criterion and the Health and Safety Executive’s endorsement of alternative testing methods for operational roles. The prevention of alternative testing puts people with colour vision deficiency at a substantial disadvantage versus colleagues without it.


This Conference calls on the General Secretary to raise this matter with the regulatory authorities without delay and to seek resolution on it. We cannot have some members being treated less favourably than others, if one sector we have recognition in can do something to deal with this then surely the others can and with papers already in circulation dated 2014 and 2020 calling into question the current testing method why has something not been actioned by now?    



At its meeting on 25th August 2022, your National Executive Committee noted and adopted the following report from its Health and Safety Sub-committee:


We note the resolution carried unanimously by the 2022 AGM.

The General Secretary is instructed to raise this matter with the regulatory authorities and rail employers without delay and to seek resolution on it. We cannot have some members being treated less favourably than others; if one sector we have recognition in can do something to deal with this, then surely the others can. As there are degrees of colour blindness, a “one size fits all” approach is inappropriate.

The General Secretary is further instructed to place any responses received before this NEC.

Relevant Branches and Regional Councils to be informed.    


I am acting in line with these instructions. Please bring the contents of this circular and the attached document to the attention of relevant members.


Yours sincerely




Michael Lynch

General Secretary