Possible Clues:

• Load of library books or groceries, say
• Amount that can be carried
• Formula One's leader evacuated after crashing, getting large blood transfusion!
• Holding capacity?
• 'Azardous bundle?
• Load of groceries?
• It's hellish having room for wife, as much as one can bear
• Toxic Cockney? It's as much as a member can take
• Fulmar (anag.)