Interim Controls and Hazard Control Strategies
Interim controls are short-term measures that reduce exposure without permanently eliminating the hazard, and they are often appropriate when full abatement is not feasible. Examples include paint stabilization (repairing and repainting deteriorated surfaces), specialized cleaning (dust removal with wet methods and HEPA vacuums), friction and impact surface treatments, safe work practices, and ongoing maintenance and monitoring. The key distinction: interim controls require sustained maintenance and reevaluation, whereas abatement is intended to be a permanent solution for the treated hazard. A designer must choose based on hazard severity, building condition, occupancy, and resources, and must build in a monitoring schedule because interim controls degrade.
Hazard control strategy follows a hierarchy: eliminate the hazard (remove or replace), then isolate it (enclosure, encapsulation, containment), then control exposure (cleaning, safe practices, education). Interim controls typically sit lower in the hierarchy and depend on behavior and maintenance. The design should specify who performs controls, the frequency of cleaning and inspection, and triggers for escalation to abatement.
Traps: treating interim controls as permanent; omitting a maintenance/monitoring plan; relying on cleaning alone without addressing the dust source; and applying interim controls to a severe hazard that requires abatement.
Rule of thumb: interim controls are only as good as the maintenance plan behind them-always pair them with a schedule and reevaluation. Worked example: a rental unit with intact but deteriorating paint on a door frame-stabilize the paint, treat the friction surface, clean with wet methods/HEPA, then schedule periodic inspection and cleaning; if deterioration recurs, escalate to abatement.