Controlling chemical hazard risks in construction projects involves several key steps, including:

1. Identify potential hazards: The first step is to identify the types of chemicals that will be used in the construction project and their potential hazards. This may involve reviewing material safety data sheets (MSDS) and conducting a hazard assessment.
2. Implement engineering controls: Engineering controls, such as ventilation systems, should be used to minimize exposure to hazardous chemicals. This may involve installing ventilation systems or using enclosed systems to minimize exposure.
3. Provide personal protective equipment (PPE): Personal protective equipment, such as gloves, respirators, and goggles, should be provided to workers who are at risk of exposure to hazardous chemicals. PPE should be appropriate for the specific chemical being used and the level of exposure.
4. Develop safe work procedures: Safe work procedures should be developed for handling hazardous chemicals. This may involve developing standard operating procedures (SOPs) or work instructions that specify the appropriate handling, storage, and disposal of hazardous chemicals.
5. Provide training: Workers should be provided with training on the hazards associated with the chemicals they will be working with, how to use PPE, and the safe work procedures that have been developed.
6. Monitor and review: Regular monitoring and review should be conducted to ensure that the controls that have been put in place are effective in controlling chemical hazards.
7. Emergency response plan: An emergency response plan should be developed in case of chemical spills or exposures. Workers should be trained on the plan and it should be regularly reviewed and updated as needed.

Overall, controlling chemical hazard risks in construction projects requires a comprehensive approach that includes hazard identification, engineering controls, PPE, safe work procedures, training, monitoring, and emergency planning.