I.-The occupational risk factors mentioned in article L. 4161-1 are defined as follows:
1° With regard to marked physical constraints:
a) Manual handling of loads mentioned in article R. 4541-2 ;
b) Awkward postures defined as forced joint positions;
c) Mechanical vibrations mentioned in article R. 4441-1 ;
2° With regard to the aggressive physical environment:
a) Dangerous chemical agents mentioned in articles R. 4412-3 and R. 4412-60, including dusts and fumes;
b) Activities performed in hyperbaric environments referred to in article R. 4461-1 ;
c) Extreme temperatures;
d) Noise referred to in article R. 4431-1 ;
3° With regard to certain patterns of work:
a) Night work under the conditions set out in articles L. 3122-2 to L. 3122-5;
b) Work in successive alternating shifts;
c) Repetitive work characterised by the performance of work involving the execution of repeated movements, using all or part of the upper limb, at a high frequency and at a constrained pace.