[Once] an employer knows, or reasonably ought to know, that one of its employee’s is a disabled person within the meaning of the Equality Act 2010, the employer is under a “duty” to make “reasonable adjustments” to ensure that the employee is not placed at a [substantial disadvantage] in comparison to those people who are not disabled pursuant to s.20(3); s.21 and s.39(5) of the Equality Act 2010. The key here is to ask yourself whether your employer is aware that you have a disability? If not, then make sure you inform the employer in your grievance letter that you have a disability/impairment.
A failure by the employer to make “reasonable adjustments” may well amount to a “breach” of its “duty of care”. Further, it may give rise to the employee claiming “breach of contract”. This could also amount to an employer’s failure to observe the “mutual trust and confidence” between employer and employee.
It is incumbent upon your employer to undertake a proper assessment of you disability in consultation with you –
Tarbuck v Sainsburys Supermarkets Ltd  IRLR 664 paragraphs 69 & 72:
 “There can be no doubt that any employer would be wise to consult with a disabled employee in order to be better informed and fully acquainted of all the factors which may be relevant to a determination of what adjustment should reasonably be made in the circumstances. If the employer fails to do that, then he is placing himself seriously at risk of not taking appropriate steps because of his own ignorance. He cannot then pray that ignorance in aid if it is alleged that he ought to have taken certain steps and he has failed to do so. The issue for the Tribunal will then be whether it was reasonable to take that step or not.”
 “Accordingly whilst, as we have emphasised, it will always be good practice for the employer to consult and it will potentially jeopardise the employer’s legal position if he does not do so- because the employer cannot use the lack of knowledge that would have resulted from consultation as a shield to defend a complaint that he has not made reasonable adjustments- there is no separate and distinct duty of this kind.”
For a list of legally recognised disabilities, click here
“Reasonable and Practicable Steps”
The employer shall take [reasonable and practicable steps] to ensure its employees’ [health and safety] whilst at work.
Section 2(1) of the Health and Safety At Work Act 1974: “It shall be the duty of every employer to ensure, so far as is ‘reasonably practicable’ the health, safety and welfare at work of all his employees.”
Let’s break down the above sentence, and see what it is actually stating.
The employers “relevant duty” is to “ensure” as is “reasonably practicable” the “health”, “safety” and “welfare” of his employees’.
A contravention of the HSWA 1974, may potentially amount to a breach of the contract of employment.