As a EMT working 24HR shifts away from home , can I deduct my meal expenses and if so how much per day.

Sorry, but you would have no deduction. 

There have been decisions on the deductibility of fireman's (EMT's would be similar) meals that have gone both ways. As the dust settles, comparing all of the cases indicates they may be deducted in a very few situations. These are:

• The deduction is only for payments into a common mess fund (not the purchase of meals themselves)
• that is required as a condition of employment by your employer, and is not contained in a union contract,
• you are required to pay for the meals whether you eat them or not, and
• the funds are maintained by the employer.

If you don't meet each of the three criteria, the meals are not deductible. In most of these plans, the payments are voluntary which would not meet the 2nd criteria.

If deductible, the expenses are a miscellaneous itemized deduction. Also, the expenses are limited to the amount paid in, not a per diem rate. In the few cases where they are deductible, they would be a miscellaneous itemized deduction for employee business expenses. Miscellaneous itemized deductions are only deductible if you itemize, and then only to the extent that your miscellaneous itemized deductions such as employee business expenses exceed 2% of your adjusted gross income (AGI).   Turbotax explains the 2% limit here. The leading case for the deduction under the limited criteria above is Sibla v. Comm.