42. No employer shall employ an employee who has not obtained the certificate of qualification required to carry on any trade or vocation contemplated in subparagraph b of the first paragraph of section 30 and such an employee shall not carry on such trade or vocation.
No skilled tradesman may carry on a trade or vocation contemplated in subparagraph b of the first paragraph of section 30 unless he has obtained the certificate of qualification required to carry on that trade or vocation.
1969, c. 51, s. 42; 1979, c. 2, s. 30; 1996, c. 74, s. 14.