Children can be inquisitive and may not recognize the potential danger around them through a lack of awareness plus there is supervision, safeguarding, working hours, welfare and other factors to consider.
Contributing to or participating in certain types of production carries risks to mental health and psychological wellbeing over and above the normal exposure to workplace stress.
Arrangements must be adequate to ensure that those disabled by the environment are not at risk.
SAs may not be experienced and know how equipment operates and/or understand the hazards on set.
Too many people on set could cause crew or equipment to be obstructed. Additional people may result in welfare provision becoming insufficient.