When Phenomenex employees in the past decade were challenged to shave their heads or dye their hair splashy colors, Chief Executive Fasha Mahjoor politely declined. But not this time.

“I never had the guts in previous years,” said Mahjoor, 62. “But all the managers cornered me and said I had to.”

The Torrance firm, which makes components for chemical testing used by food and drug companies, told employees it would donate $500 to a charity of their choice every month that each of them kept their hair dyed or their head shaved.

Nearly 50 people have taken part, shearing their locks or dying them purple, green and even zebra striped.

The challenge ends in October; Phenomenex is on track to raise up to $160,000.

In the interim, Mahjoor is still sporting the cue-ball look.

“Every time I look in the mirror, I sort of get a shock,” he said.

Mahjoor will have to bare it a little longer, something that might be a little uncomfortable when he’s rappelling down three London skyscrapers in September for another charitable event.

“I hope it’s not windy,” he worried. “My head gets so cold.”

Going to Bat

Ben Affleck and Christian Bale bump into each other in a Hollywood costume shop …

It sounds like the opening line of a joke. But the latest Batman revealed that’s actually how he encountered his predecessor in the role.

“We were both in there at the same time shopping for Halloween costumes for our sons,” said Affleck, 42. “And so I took the opportunity to ask Christian if he had any tips for me about taking on the part.

“He replied, ‘Make sure you can use the bathroom in that suit!’

Bale’s blunt advice turned out to be sound, and that’s why Affleck’s superhero costume had a strategic zipper built in for use during production of Warner Bros.’ upcoming “Batman vs. Superman.”

He told the story while promoting the film at San Diego Comic-Con, where Superman actor Henry Cavill said he followed his co-star’s lead and now his costume also has a special zipper.

In between trips to the restroom, the two superheroes will be duking it out in the film, set for release in March.

Staff reporters Marni Usheroff and Sandro Monetti contributed to this column. Page 3 is compiled by Editor Charles Crumpley. He can be reached at [email protected].