The phrase "are necessary to avoid" is correct and usable in written English.
You can use it when discussing actions or measures that must be taken to prevent a particular outcome or issue.
Example: "Certain precautions are necessary to avoid potential hazards in the workplace."
Alternatives: "are essential to prevent" or "are required to avert".
High pH conditions are necessary to avoid excessive sulfate leaching.
"Drastic politics are necessary to avoid hemorrhage, currency collapse and irreparable meltdown".
"But they are necessary to avoid permanent damage to the federal defender program," he wrote.
Take the steps that are necessary to avoid us taking the steps we are prepared to take".
As severe stresses result with the present design mitigating measures are necessary to avoid damage and maintain proper operation.
Richard M. Kessel, the LIPA chairman, has warned that new power plants and transmission lines are necessary to avoid future power shortages.
Therefore, predictive in vitro and ex vivo placenta models using human cells or tissue are necessary to avoid species-specific differences.
The strong dipolar groups acting as associating groups are necessary to avoid polymer molecules forming dense aggregates and precipitating from the solutions after phase separation.
In addition, sufficient project storage areas are necessary to avoid confusion, theft, damaged projects, and general discontent among the employee population.
Gov. George E. Pataki and his aides have argued that the generators are necessary to avoid sharp jumps in electricity prices like those last summer, and even possible blackouts.
The government is also committed to combating climate change, but by most accounts its proposed Direct Action Plan cannot achieve the pollution cuts scientists tell us are necessary to avoid dangerous a future that threatens farmers' livelihoods.
