In Ingrid Chin v. Mt. Sinai Medical Center and York Risk Services Group Claimant was exposed to a fire extinguisher discharge causing shortness of breath on 2/13/18. E/C accepted Claimant’s accident as compensable and authorized treatment. On 11/29/21, E/C denied Claimant’s claim for return visit with treating doctor stating the treatment is unrelated to the work incident and the doctor discharged Claimant from his care. Claimant asserts E/C waived the right to deny compensability based on the 120-day rule. The E/C asserts the the 120-day waiver defense is inapplicable to the instant case as E/C never elected to pay the claim pending investigation. E/C also asserted that there was a break in the causal chain and the requested treatment was due to a condition unrelated to the injury. The JCC found that the E/C waived the right to contest compensability based on the 120-day rule and E/C did not establish a break in the causal chain. Authorization of medical appointment and prescription medications GRANTED.